Tensei Shitara Shima Kousaku Datta Ken

After being killed by a passing robber, a normal 37-year-old guy finds himself reincarnated as Kousaku Shima in 1984.

Note: The volume contains the only 2 chapters of the spin-off, 2 chapters of the manga Kachou Shima Kousaku, and one chapter of the manga Tensei Shitara Slime Datta Ken