Hug Kiss Hug

Youko Kihara makes the resolution to say goodbye to her longtime affair partner after seeing her friend's marriage. Later on she gets ambushed by him in front of her house, and is saved by Fujiwara, a resident of the same apartment. Fujiwara snuggles up to Youko, who is filled with anxiety, until she falls asleep...? He says he will sleep with her when she is unable to sleep in the future.

(Source: Kodansha, translated)