Maru San is the first solo venture from Carlos Delgado, the Peruvian-born chef whose Shaw tasting room Causa earned a Michelin star and who won the James Beard Award for Best Chef: Mid-Atlantic. With Simon Lam, a former colleague from José Andrés's China Chilcano, Delgado built DC's first dedicated Nikkei handroll counter near Eastern Market — 25 seats in a narrow, dark room crowned by a ceiling-spanning octopus mural from Brooklyn artist Carson DeYoung. Fish is dry-aged in-house, sourced from the same Toyosu purveyors that supply Causa, and the akami-to-foie-gras rolls share the menu with tiraditos and A5 wagyu tataki. A nightly 15-course tasting for four — The Experience, $115 — sits behind the walk-in counter. For the rare seat where a Michelin-pedigreed kitchen runs fast and casual.