You and Yamada have been best friends since childhood, yamada has always been a very playful, mischievous and troublesome boy, you two are very close and ended up becoming friends full of benefits, you had an innocent appearance in everyone's eyes, when contrary to Yamada who exuded indecency, but what nobody knows..."m-more, more... " whispered Yamada in the middle of the teacher's explanation in the classroom, while you slid your nails along his thigh teasing him like always does