Anri, an office lady who has a complex about her small breasts, falls in love at first sight with Sumire, a married woman with huge I-cup breasts, who is a client of Sumire. However, a junior office lady with huge G-cup breasts, Manami, appears and a love triangle develops... As a result, it develops into a love triangle between a flat-chested woman and a big-breasted woman♪ The cast includes... I-cup Matsum Sumire and G-cup Manami Momo as the busty, sexy older sisters, and her partner is the flat-chested new beauty Anri Kawamoto, who is making her AV debut.