Merman in My Tub: The Seven Transformations of my Bathtub Circumstances

When Wakasa asks if something good happened, Tatsumi shyly admits his manager gave him a raise and allows Wakasa to splurge a little. Wakasa grins at Tatsumi's offer to splurge, and Tatsumi buys Wakasa a massive amount of milk. While Wakasa enjoys his milk bath, Mikuni, Maki, and Takasu arrive...