Mina is bored and has no place at home, so she devotes herself to work to relieve her loneliness. Her colleague Asano falls in love at first sight with Mina's kind and sincere demeanor and exceptional beauty. Asano proactively talks to Mina to cheer her up when she sees the sad expressions she sometimes shows. Such a strong and single-minded feeling melts Mina's cold heart... and she steps into a line that she must not cross.