Dark Gathering, Vol. 1

Keitaro is ready to stop living as a shut-in. He's starting university. He's reconnecting with his childhood friend. He's taking a tutoring job. And he's not messing around with ghosts anymore. At least that's what he thinks, until he finds out the elementary schooler he's tutoring is an occult-obsessed genius who's hunting down dangerous spirits and won't stop until she's found the one that took her mom!

Volume 1 of the Dark Gathering manga series by Kenichi Kondo.