Dandadan. Volume 9: Yukinobu Tatsu

A nerd must fight powerful spirits and aliens all vying for the secret power of his “family jewel,” so who better to fight alongside him than his high school crush and a spirit granny?!
Momo Ayase and Okarun are on opposite sides of the paranormal spectrum regarding what they’ll believe in and what they won’t. Their quest to prove each other wrong leads them down a path of secret crushes and paranormal battles they’ll have to participate in to believe!
A seemingly unbeatable kaiju is on the attack! Okarun hits on the idea of revisualizing the nanoskin that repaired Momo’s house into a form they can use to fight back, but he lacks the imagination needed, so it’s Kinta Sakata—a.k.a. Erosuke—to the rescue! The nerd uses his vast knowledge of sci-fi to transform Momo’s house into…a giant Buddha robot?!