On the Compatibility Between Magical Girls and Vongola BOSS

Tutoring fan, male protagonist 27 Sawada Tsunayoshi arrived ten years later and discovered: My future self becomes the leader and then... Parents are missing The world is going to end Kurokawa Hana and Kyoko's brother are still married The girl he doesn't know very well in the next class is actually his future girlfriend? Um? Wait, is something wrong? Why is his girlfriend (future) a magical girl? Purpose: Cherish others and cherish yourself