Level 1 no Dakarekata

Game planner Hidaka has always wanted to take down his colleague and rival, Ouno. When he discovers that Ouno is actually gay and tends to lose focus on work when he has a lover, Hidaka sees an opportunity. “This is my chance!” he thinks and decides to disguise himself as “Shiki,” a college student, to approach Ouno and become his “ideal lover.” Hidaka manages to deceive Ouno, but as an inexperienced romantic, he quickly finds himself outmatched. On the very day they meet, he is overwhelmed by Ouno’s advances, leaving him weakened and unsure of how to proceed...!

(Source: Core Magazine, translated)

Note: Includes one extra chapter.