Kamiizumi Nobuyuki

A normal High School student in the modern years, who died in a traffic accident. He ends up reincarnating into the past in the body of a samurai warrior in the Edo period. He retains all memories of his previous life, but also attains a secret katana technique from the samurai that makes him an unstoppable warrior. Under his new life in Japan's past, he meets pretty girls and strange people on his journey to uncover the mystery of a 'hidden treasure.'

Spoiler

in Tamaki route, it's reveal Nobuyuki and Tamaki came to Edo period via body swap method with hidden treasure "Soul reflection mirror (反魂鏡)".
and switch between Real Kamiizuki Nobuyuki and Mitsui Tama's soul.
They did total 3 time.
1. in Kamikakushi case and traffic accident.
2. in last fight with Muramasa, Tamaki switch herself and Nobuyuki 's soul.
3. Back to their original periods.
After back to modern years he join Kendo club and meet Retsuzan again.