Koyori Hoshi was left heartbroken when her boyfriend suddenly ended the relationship they had shared for two-and-a-half years. To cope with her misery, she turned to drowning herself in alcohol and venting to her childhood friend, Hijiri Akiyama. After drinking a little too much, Koyori woke up to a startling discovery - she and Hijiri were lying naked beside each other. Realizing the gravity of the situation, she was struck with the realization that their act was irreversible.
Initially chalking it up to a rebound fling, Koyori soon began to question the feelings she had subconsciously harbored for Hijiri all her life. After reflecting on their relationship, the two agreed to try out a romantic relationship.
However, their current dynamic as friends made things a little more complicated. Honnou Switch explores the complex situation that Koyori and Hijiri find themselves in as they navigate their newfound romantic relationship while trying to preserve their friendship.