Kaidou Arukun desu

Kitagawa is a salaryman who moves into a super cheap apartment in Tokyo. However, the property is haunted by a ghost! To help the ghost, Omichi, find peace, Kitagawa promises to uncover the truth behind her death and fulfill her last wishes. However, the only clue he has is Omichi's memory of walking along the Tokaido Highway in the Edo period. Kitagawa, Omichi, and Yajima, a colleague who loves the Tokaido Highway, embark on a "Tokaido Walking Trip" filled with laughter and history in order to find the clue that will lead them to the repose of their souls!

(Source: Kodansha, translated)