Site of Mizuno Kenmotsu Residence, Archaeological site from Edo period in Shiba, Japan.

The Site of Mizuno Kenmotsu Residence in Shiba 5-20-20, Minato, Tokyo, is a fenced plot marking the middle residence of the Mizuno family, lords of Mikawa Okazaki and later Hizen Karatsu. No foundations or garden remains survive: only a stone lantern placed after the residence was moved, a bilingual information board from the Heisei era, a round stone of unknown origin and a wooden bench.

The residence was the middle estate of the Mizuno family, lords of Mikawa Okazaki and later Hizen Karatsu. In 1703 nine of the 47 rōnin from the Genroku Akō incident were placed here awaiting the shogunate's decision and committed seppuku on 4 February; the actual spot lies about 50 m north. The estate burned in 1703 and the family moved after the 1843 Mizuno disturbance.

The site is remembered for the nine Ako ronin entrusted here in 1703 while awaiting the shogunate's decision after the raid on Kira Yoshinaka's mansion; they took their own lives in this residence on 4 February 1703. Mizuno Tadayuki is said to have treated them courteously. The actual site of the seppuku lay about 50 metres north of today's marker.

The marker stands on the street in front of a clinic where Keio Nakadori bends southeast from Shiba 5-chome toward Tamachi. The actual site of the 1703 seppuku lies about 50 metres north of the present stone lantern and bilingual panel, so look for that spot separately. It is an open roadside location with no gate or staff.

The actual site of the ronin's seppuku lies about 50 metres north of this marker; the residence was moved after the Mizuno disturbance of 1843. The present plot holds only a stone lantern placed after the relocation, a bilingual information board, a round stone of unknown origin and a wooden bench.