My Childhood Friend Is Always Down Whenever I Make a Move

"Shall we pick up where we left off... at Shunta's place?" Maria Watase is a beautiful girl who is immensely popular with the boys, while Shunta Arima is a geeky high school freshman. The two are childhood friends who used to play together every day for as long as they can remember. Though they had grown distant due to an "incident" back in their second year of middle school, they find themselves sitting next to each other after a seat reshuffle in high school. One day, Maria suddenly asks Shunta, "If you want to see my breasts, should I show them to you?" After school, in Shunta's room, Maria says, "I'll only show my body to you, Shunta," and begins to take off her uniform, revealing her developed chest right in front of him... (Source: Kadokawa, translated)