[Shiina Koharu's Lesbian Debut] When Koharu hears that her childhood friend Jun has started dating someone, she's surprised to learn it's a woman but wishes Mizuki happiness nonetheless. One day, Jun begs her to let him practice with her because he has never done anything sexual with another woman. Koharu is weak to pressure, and agrees to practice cunnilingus with Jun, saying, "On top of my clothes..." However, Jun's cunnilingus becomes more and more extreme, and the moment he licks her pussy, ...