Toraneko Folklore

All through middle school, Touto was the tough kid that people either fought, feared, or avoided. Resolving that his high school life will be different, he studied hard and entered a prestigious high school. Despite his harsh demeanor and odd behavior, he manages to make two friends right off the bat, two hopeful students who are also trying to recreate themselves. Timid Miyakoe, who is interested in the occult, was always overlooked in middle school, and she wants her presence to matter in high school. Chubby Yuta wants to erase his school history of being constantly bullied.
Everything is going well until Miyakoe disappears while investigating a scary school myth. Going after her, Yuta and Touto encounter a dangerous cellphone monster! When all seems lost, Touto's cellphone-strap good-luck charm comes to life to give him the strength to defend his new friends. It seems that Touto's high school life is going to be much stranger than he could have ever imagined!
(Source: MangaHelpers)