悠樹 里久

Protagonist of Lost Echoes. 

After the death of his parents, he inherits his father's photo studio and lives together with his sister, Yuuki Akiho. 

One day, he informed by a deity that his childhood friend, Tachibana Yuika, is in the verge of being cursed. He learns that the only way to avoid that is by going back in time and prevent a certain incident from happening. He then makes an agreement with the deity to retain her lost relic, Ryuuju, which makes time travel possible.

When he goes back to the past, he mainly inherit Head Priest Housei's memories along with his background. However, due to the relic's power, he still retains his actual body from modern time and people around him refer him by "Riku" instead of "Housei", making him non-blood-related brother of Tachibana Ginchiyo.