Although he is the son of legendary detective Tatsuya Outsuki, Sakuya avoids dangerous investigations at all costs. He considers his father's exploits an example of what not to do, preferring cases that deal with adultery or finding lost cats.

During one such safe investigation on a cruise ship, Sakuya discovers a dead body. Despite his misgivings, he begins to look into it. However, he is brutally murdered before he can get far. Not long after, Sakuya wakes up to his assistant, Lilithea. This is not his first death—as it turns out, every time he dies, he revives sometime later. Thus, Sakuya continues his investigation, being both detective and victim.

As he wraps up the case, Sakuya witnesses a horrendous plane crash—the same plane his father was supposed to be saving. Now in charge of their detective agency, Sakuya endeavors to discover the truth behind his father's demise. Starting with the Seven Old Men, a group of criminals Tatsuya imprisoned, Sakuya will solve the mystery, no matter how many times he dies.