The scenario is basically, a high school boy's female childhood friend turns out to be a succubus in training, and he is the one she picked as her first partner, happy sex with love follows on the school rooftop.

(Source: Hentairules)

1-6. Succu Life (さきゅらいふ)

7. Succu Life Gaiden (さきゅらいふ 外伝)

8. Kinensai (祈年祭 )