Dandadan 6 Books Set by Yukinobu Tatsu (Vol 1-6)

Vol 1
Momo Ayase strikes up an unusual friendship with her school’s UFO fanatic, whom she nicknames “Okarun” because he has a name that is not to be said aloud. While Momo believes in spirits, she thinks aliens are nothing but nonsense. Her new friend, meanwhile, thinks the exact opposite. To settle matters, the two set out to prove each other wrong—Momo to a UFO hotspot and Okarun to a haunted tunnel!

Vol 2
Okarun, a high school boy obsessed with supernatural phenomena, is cursed by Turbo Granny! Along with his classmate Momo Ayase, he challenges Turbo Granny to a game of tag as a means to lift the curse. If the two can stay out of her reach until the finish line, they’ll win.

Vol 3
Okarun, a high school boy obsessed with supernatural phenomena, has lost his precious family jewels in a battle with Turbo Granny! His classmate Aira ends up finding one, and it awakens spiritual powers within her.

Vol 4
The banana-stealing Serpoians are back! And they’ve trapped Okarun, Momo, and Aira in a void to have another go at stealing their reproductive organs. The subsequent battle causes the powers of the Acrobatic Silky dwelling within Aira to awaken, and she temporarily joins forces with Momo and Okarun.

Vol 5
Okarun and the gang are off to a hot springs town to investigate the mystery of Jiji’s family. But when they get there, a strange family in cahoots with the police starts causing trouble for them, and before Okarun and the others can get to the bottom of the mystery, Momo ends up as an offering to the local god!

Vol 6 

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!

The Kito clan tosses Okarun and the gang into an alternate-reality version of Jiji’s family home as an offering to the serpent god! There they encounter another of the clan’s sacrifices, a child who goes on to possess the softhearted Jiji. The two of them become the Evil Eye, who then attacks Okarun and Momo. Okarun decides to take him on alone and sends Momo back aboveground to get help. There she comes up with an ingenious plan to get rid of the giant serpent god…but can she pull it off on her own in time to save Jiji?