Sequel & Spin-off

Part 2
Yura x Kaji

Part 1
Two months after coming to Tokyo, Iku is enjoying otaku life, but something mysterious is happening to him: He's started to see ghosts!

Part 2

Part 1
Ashitaka x Noshiro

Part 2
Rui x Saeki

Part 3
Kazunari x Ui
- age gap

Part 1
1-2.5: Kojima x Kuruta - Kojima is a Vice President who carry the stress of his father expectation and have sex to relieve it, but Kuruta show him another way to relieve the stress by taking him to an arcade.
3-5: Kota x Hiroto - step brother, Hiroto (younger bro) fall in love at first sight when he saw Kota (older bro), but he's quiet so he couldn't express himself properly.
Side couple: Kaji x Retsu - Kaji (student president) and Retsu (secretary)

Part 2
Kaji x Retsu - story of how they got together
Side couple: Kojima and Kuruta

Part 3
1: Kaji x Retsu: Retsu meeting after Kaji graduation at Kaji's dad hotel pre-opening party, they ditch the party and had sex
2: Kojima x Kuruta - Being together on the day before New Year
3: Kota x Hiroto: Spending summer vacation together at grandparent house (grandparent left to go on a cruise)

Part 1
Endo x Rikiya
- Demon x Human