The era when old Edo is gradually changing into Meiji. In the Matsushita estate, an old family home, lives the only son and heir, Sennosuke Matsushita. While suffering from insomnia due to mental exhaustion, he faces the family business and ledgers inherited from his father by day, and reads books in his study by night, unable to sleep.

In this old house, Sennosuke and Guest exchange words, walk the streets of Edo, and spend their days watching the shifting era. The bustle of Nihonbashi, the clamor of Asakusa, the bookstores of Kanda, the sunset over the Sumida River, rain-drenched alleys, and the quiet veranda at night. Soon, signs of a new era—Western clothes, brick buildings, railways, and gas lamps—creep into the city. While old things remain, the scenery that was taken for granted until yesterday changes bit by bit.

Spend free days with a sleepless young master in Edo, caught in the gap between eras. (Guest's setting is free: a live-in guest, childhood friend, student, boarder, cat, etc.)