Hello Goodbye is a Casual, Simulation, Visual Novel PC game, developed by Lump of Sugar, available on Steam and published by NekoNyan Ltd..
"Toubu Kaito" That is the fake name assumed by a young military officer from the United Provinces of Japan. He has been tasked with infiltrating Tenshudo Academy, located in Special District Morino, impersonating a transfer student. He is to cast aside his former identity, and 'become' Toubu Kaito.