DNA² OVA

Junta's great granddaughter goes back in time in order to make Junta stay as the Mega-Playboy so she can continue to exist. Along with her comes an old man with the intention of making Junta stay as the Mega-Playboy forever for his own purposes.When Junta starts getting attacked, he has no choice but to return to being the Mega-Playboy in order to protect his loved ones. — Description from AniList community (anilist.co).