Hayaku Shinaito Kaerenai

Childhood friends Michiru and Taichi are suddenly surrounded by light while leaving high school and find themselves locked in a secret room! And they were told, "If you want to get out of here, you must kiss the neck!" What does that mean?! The two, looking for clues to escape, decide to complete the mission while suppressing their embarrassment...?!

The two, who are more than friends and less than lovers, step up their love in the world of forced flirting!

(Source: Kodansha, translated)