While feeling stupid for believing in his words and becoming unable to believe in the word "love" anymore, she suddenly received a love confession from Okuma, a junior colleague. To have her believe in his confession, Okuma promises to sincerely tell her "I love you", once a day and every day. Not knowing where and when she'll be told "I love you", a surprise-filled office love story begins between Haru and Okuma, who is unexpectedly bold despite his seemingly unfriendly and fierce look.