Out of sight and out of mind, this Japanese restaurant is very nearly the low-key Fuji-alternative Siam called for. Propped between old-school names Ping’s (Thai-Teochew) and Kongju (a BK four-star Korean) on the second floor of the Pathumwan Princess Hotel, Tatsumi feels positively tucked-away, despite sitting just a security check away from the throngs of MBK mall.

Since opening in late 2016, the restaurant has made all the right noises about fish flown in from Tsukiji several times a week and an executive chef with 30 years’ work for Okura hotels and as private chef to the former Japanese ambassador to Thailand. Yet, Tatsumi feels more in line with the charmingly dated, jack-of-all-trades Japanese canteens of Thaniya or middle-Sukhumvit than the swanky new breed of omakase openings.

The greatest-hits menu (sashimi, sushi nigiri, maki, tempura, nabe hot pot, tonkatsu) seems to confirm this, even if seasonal chef’s selection sets (like the current Fuyu tasting menu, B1,900 for eight courses) hint at loftier ambitions. Our last visit, a Friday night, found the wooden sushi counter empty and the quarter-full dining room in full drinking mode, doted on by swift, hotel-efficient waitstaff.

We’d like to say Tatsumi excels at all the basics, like serving up fresh fish, but a frost-tinged salmon sashimi (B220) last time out gave us pause. That’s not to say the otoro (B320 per piece) or yellowtail (B120) nigiri completely disappoint, but Bangkok sushi-philes now demand more than reasonably fresh slithers of fish and slightly mushy rice.

When the restaurant goes for more fireworks, as in various “signature” rolls featuring blowtorched fish and sweet, fatty sauces, the results aren’t hugely exciting, but nor are they disastrous. Not one for the purists, the Tatsumi roll (B1,150 for eight pieces) is equal parts smoky, gloopy unagi (freshwater eel), briney ikura (salmon roe) and crunchy botan ebi (deep-fried sweet shrimp)—and it just about works, with a pair of massive edible shrimp heads as the unexpected highlight.

From the hot kitchen come more comforting notes: oyster nabe (B350) with a toothsome dashi and bonito broth; tempura moriawase (plump shrimp and mixed vegetables, B350) that’s crisp, but light on flaky delicacy. Yet, barring an excellent homemade umeshu (plum wine, B220/glass), Tatsumi doesn’t really offer much that isn’t done better at second-tier sushi names like Sushi Mori or Sushi Hiro, lending the plethora of all-you-can-eat and half-price deals a certain air of desperation.

This review took place in February 2018 and is based on a visit to the restaurant without the restaurant's knowledge. For more on BK's review policy, click here.