Mehikari (Greeneye Fish) — What It Is, and the Karaage Japanese Homes Make

If you’ve come here because you saw the word mehikari somewhere and wanted to know what it is: it’s a small deep-sea fish caught off the Pacific coast of Japan, sold whole, and named for its enormous eyes, which shine green when the light hits them. In English it’s called greeneye. It’s a regional fish, it isn’t sold everywhere even in Japan, and when I find it I buy it immediately.

This post is both things: what mehikari actually is, and what we do with it at home in Kyushu — karaage, deep-fried whole at a low temperature until the bones are soft enough to eat. If you’re only here for the recipe, skip to Fish Karaage: The Recipe.

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What is Mehikari (Greeneye Fish)?

Mehikari (メヒカリ, also written 目光) is a small deep-sea fish, usually somewhere around 10–15 cm (4–6 inches) long — small enough that two or three of them fit in your palm. The body is slender and silver, a little soft to the touch, and the head is dominated by a pair of very large round eyes. Its standard Japanese name is aome-eso (アオメエソ), and in English it’s known as a greeneye, from the family Chlorophthalmidae.

It’s sold whole, ungutted, usually on a supermarket tray with fifteen or twenty fish on it. It is not a premium fish and it isn’t expensive — the tray in these photos was ¥1,173 — but it’s a genuine local specialty, and in the places where it’s landed people are proud of it.

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Why It’s Called “Greeneye”

The Japanese name is literal: me (目) is eye and hikari (光) is light — “shining eye.” Mehikari lives in deep water where almost no sunlight reaches, and like a lot of deep-sea animals its eyes have a reflective layer behind the retina that bounces light back through it, the same thing that makes a cat’s eyes flash in headlights. The result is that a dead fish on a supermarket tray still has eyes that glint green-blue when you tilt it toward the light. It’s genuinely striking the first time you see it, and it’s the reason English-language fish books call the whole family greeneyes.

Where It Comes From

Mehikari is trawled from deep water along Japan’s Pacific side. The fish I buy comes from Oita Prefecture, on the east coast of Kyushu — the same prefecture as tori ten, the chicken tempura that’s the other thing Oita is known for in a fryer. Mehikari is also strongly associated with Iwaki in Fukushima Prefecture, where it’s the official city fish, and it’s landed in Miyazaki, Kochi, and Shizuoka as well.

What that means in practice is that this is a fish you meet regionally rather than nationally. It’s an izakaya staple in the areas where it’s caught and close to unknown in the areas where it isn’t.

What It Tastes Like

Mild, faintly sweet, and much richer than its size suggests. The flesh is white and unusually soft — almost creamy — because it carries a good amount of fat for such a small fish. There is no strong “fishy” smell at all, which surprises people who expect a small oily fish to taste like sardines. It doesn’t. If you have ever eaten shishamo, mehikari sits in the same territory but softer and less mineral.

The softness is also why it’s almost always fried. The flesh is too delicate to grill well and falls apart if you simmer it, but it’s perfect in hot oil.

When Can You Buy It?

Honestly: whenever it turns up. In Kyushu I mostly see it in the colder half of the year, but I can’t plan meals around it — some weeks the supermarket has a tray of it and most weeks it doesn’t. It’s a by-catch-adjacent, locally landed fish rather than something stocked year round, so buying it is opportunistic. That’s part of why I cook it the moment I see it.

Can You Get Mehikari Outside Japan?

Realistically, no. Mehikari is barely distributed nationally within Japan, let alone exported, and I have never seen it in an overseas Japanese grocery. If you want to make this dish where you live, the fish is not the point — the method is. Use any small whole fish that can be eaten bones and all:

• Smelt — the closest common substitute in the US and Europe, and sold whole almost everywhere.
• Shishamo — sold frozen in Japanese and Korean groceries; slightly firmer and saltier.
• Small whiting, sand lance (ikanago), or small horse mackerel (aji) — all take the same coating and the same low fry.

How Mehikari Is Eaten in Japan

Karaage is the most common preparation by a distance, but it isn’t the only one. If you’re in Japan and see mehikari on a menu, this is roughly what you might be looking at:

• Karaage (唐揚げ) — dusted in potato starch and deep-fried whole. The default, and the recipe below.
• Tempura (天ぷら) — battered rather than dusted, lighter and more delicate, often served with salt rather than dipping sauce.
• Nanban zuke (南蛮漬け) — fried first, then marinated in a sweet-and-sour vinegar sauce with onion. It’s excellent with mehikari and it keeps for days. I have a full nanban zuke recipe made with a different fish; the method transfers directly.
• Himono (干物) — split and dried overnight, then grilled. This is common around Iwaki and is one of the few preparations that isn’t fried.
• Sushi and sashimi — possible where it’s landed fresh enough, but rare, because the flesh is so soft. If you see it raw, you’re near the boat.

Fish Karaage: The Recipe

Fish karaage — small fish seasoned, dusted in potato starch, and deep-fried until crisp enough to eat whole — is one of the most satisfying things you can make with cheap fish, and it’s a classic izakaya snack. This is the version I make with mehikari, but the same method works with any of the substitute fish above.

Ingredients (Serves 2–3)

Ingredient	Amount	Notes
Mehikari (or other small whole fish)	240 g / about 8 oz	Roughly 15–20 fish
Potato starch (katakuriko)	2 parts	About 4 tbsp for this amount
All-purpose flour	1 part	About 2 tbsp
Salt and pepper	To taste	Go light — the fish is clean-tasting
Neutral oil	For deep frying	Vegetable or canola

The coating is the only thing you need to buy: potato starch (katakuriko) on Amazon is what makes karaage crisp rather than bready, and it’s worth having in the cupboard permanently — it thickens sauces and coats chicken karaage too, so it earns its shelf space. It’s on my list of Japanese pantry essentials. For the frying itself, a deep, narrow deep frying pot on Amazon uses far less oil than a wide pan and makes holding a steady 160°C much easier.

The Coating Ratio

I use 2 parts potato starch to 1 part flour. This is my go-to ratio for fish karaage. The potato starch creates a lighter, crispier shell than flour alone; the flour adds a little body and helps it brown evenly. All starch can be brittle, all flour can be dense — the 2:1 is the middle.

Step 1: Clean the Fish

Mehikari are small, but they do need prep. I remove the scales, the head, and the innards.

1. Remove the scales with the back of a knife, running it lightly along the skin from tail to head. The flesh is soft, so be gentle — you don’t need much pressure.
2. Cut off the head with a knife, just behind the gills.
3. Remove the innards — open the belly and pull them out. Rinse each fish under cold water.
4. Pat dry with paper towels. This matters more than anything else for a crisp coating.

Another method: some people skip the knife entirely and pull the gills out with their fingers — the innards come along with them. It’s a standard technique for small fish and it’s fast once you get the hang of it. Either way works.

The skin stays on. The bones are small enough that they go soft when fried at low temperature, so the whole fish gets eaten.

Step 2: Season the Fish

Lay the cleaned fish on a tray and season lightly with salt and pepper on both sides. Don’t overdo the salt — the coating adds some, and mehikari has a clean flavor you don’t want to bury.

Step 3: Coat in the Starch Mixture

Mix 2 parts potato starch with 1 part flour in a bowl. Add the fish a few at a time and toss to coat evenly, then shake off the excess. You want a light, even dusting, not a thick crust.

Step 4: Fry Low and Slow

Heat the oil to around 160°C (320°F). This lower temperature is the key to the whole dish.

Why low? Because the fish are small and the flesh is delicate. At high heat the outside browns before the inside is done. At 160°C you get a gentle, even fry that cooks the fish all the way through to the bone — which is what makes those small bones soft enough to eat.

Fry for about 10 minutes, turning occasionally, until the coating is golden and crisp. You’ll hear the sizzling calm down as the moisture cooks out; that’s the signal they’re nearly there.

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Step 5: Drain and Serve

Transfer to a plate lined with paper towels and let them rest a minute to drain. Serve immediately while hot — the coating holds for a while, but like all karaage it’s best straight away.

Tips from My Kitchen

• Pat the fish dry before coating. Moisture is the enemy of a crisp crust. Even a quick pat makes a real difference.
• Don’t crowd the pot. Fry in batches. Too many fish at once drops the oil temperature and you get soggy coating.
• 160°C is not a typo. It sounds low. For small whole fish with bones, slow and steady wins — fully cooked fish, soft bones, golden crust.
• Eat it whole. After 10 minutes at 160°C the bones are soft. Take the whole fish in one or two bites; that’s how it’s done here.
• Buy it when you see it. This isn’t a fish you can plan around. If the supermarket has it, that’s dinner decided.

What to Serve It With

At our house it’s an okazu — a dish alongside rice and soup rather than the center of the plate. A wedge of lemon on the side is good, and some people like ponzu. I usually eat it plain.

• As dinner — with rice, miso soup, and one vegetable side.
• As a drinking snack — this is classic izakaya food, and beer is the standard partner.
• In a bento — on the rare occasion there are leftovers, they reheat decently in a toaster oven.

For more fried food from this part of Japan, tori ten is the other Oita specialty worth making, and ebi fry covers the panko side of Japanese frying.

Storing and Reheating

Fish karaage keeps in the fridge for a day or two in an airtight container, though it’s really a same-day dish. Reheat in a toaster oven or air fryer for a few minutes to bring the coating back; the microwave turns it soft and slightly rubbery. Cold karaage straight from the fridge is also perfectly good in a bento — that’s how a lot of it gets eaten in Japan anyway. Don’t freeze it: the flesh is too soft and comes back watery.

Frequently Asked Questions

What is mehikari in English?

Greeneye. It’s a small deep-sea fish of the family Chlorophthalmidae; the Japanese standard name is aome-eso (アオメエソ) and mehikari (メヒカリ) is the common name, meaning “shining eye.” You’ll occasionally see it written as “Japanese greeneye” on menus translated for tourists.

What does mehikari taste like?

Mild and slightly sweet, with soft white flesh that’s richer and fattier than you’d expect from a fish this size. It has no strong fishy smell. Fried, it tastes closer to a delicate white fish than to an oily one like sardine or mackerel.

How big is a mehikari?

Around 10–15 cm (4–6 inches) — roughly the length of your hand. A 240 g tray holds about 15 to 20 fish, which is enough for two or three people as a side dish.

Do you eat mehikari bones and all?

Yes — that’s the whole point of frying small fish this way. Ten minutes at 160°C softens the spine and fins enough to eat, so the fish goes down in one or two bites. If the bones still feel sharp, the oil was too hot or the time too short.

What can I use instead of mehikari?

Smelt is the closest widely available substitute, and shishamo works well if you have a Japanese or Korean grocery nearby. Sand lance, small whiting, and small horse mackerel (aji) are all good. The rule is simply: small, whole, and soft-boned.

What is fish karaage?

Fish karaage is the Japanese method of deep-frying fish that’s been lightly seasoned and dusted in potato starch, often with a little flour mixed in, giving a light crisp shell and tender flesh inside. It’s a dusting rather than a batter, which is what separates karaage from tempura.

What fish is best for karaage?

Small whole fish make the best karaage because you can eat them bones and all — mehikari is my favorite, but smelt, sand lance, and small horse mackerel all work beautifully. For a larger fish, cut boneless fillets such as mackerel or a firm white fish into bite-size pieces and fry them hotter and faster, around 180°C.

Is fish karaage healthy?

It’s deep-fried, so it isn’t a light dish. That said, small whole fish are rich in protein, calcium, and omega-3s, and there’s no batter here — just a thin starch coating that absorbs far less oil than a flour or tempura batter would.

Why is my fish karaage not crispy?

Almost always one of three things: the fish wasn’t patted dry, the coating was too thick, or the pot was crowded so the oil temperature crashed. Dry the fish properly, shake off the excess starch, and fry in small batches.

What do you serve fish karaage with?

A wedge of lemon, a pile of shredded cabbage, and a beer is the standard izakaya set. As a meal, serve it with rice and miso soup. It’s also good cold in a bento the next day.