This wooden residence, next to Nogi-jinja, is where General Nogi and his wife committed ritual suicide on the death of Emperor Meiji. It's open to the public only on 12 and 13 September, but the rest of the year you can peek through its windows and notice the mash-up of Japanese and Western styles that defined the Meiji period (think a tatami room with a Western fireplace).
General Nogi’s Residence
Roppongi, Akasaka & Around