Shota moves into an apartment where the new manager, big-breasted Hikari, quickly captures his heart with her looks and sweet demeanor. Their time together under the kotatsu transforms from ordinary moments into an intimate, private world. Shota can't resist playing naughty pranks—reaching under her clothes, touching her body, poking her large breasts with his fingers. His bold actions catch the attention of other male residents, and soon they too begin pursuing the beautiful Hikari. As relationships within the apartment grow increasingly tangled, desires intertwine and passions rise.