Period wo Matte Wait for the Period

Synopsis

"Senpai, you're adorable when defenseless." Yasuhara is a kind salaryman whose love life seldom works out. He's strangely attracted to his popular junior, Kurose. When a female employee asks Yasuhara out on a date, Yasuhara decides to have dinner with Kurose as "practice." He's supposed to be learning how to be popular, but for some reason he ends up having a one-night stand with Kurose...! (Source: Futabasha, translated)