少数精鋭のボディガード会社に勤める要人警護＝ボディガードのスペシャリスト・北沢辰之助。運動神経抜群で、いつも現状の２手３手先を読み、冷静沈着な判断力で活躍する会社のエース的な存在。かつて警察官だった父が殺され、未だ捕まっていない犯人を追いながら働く辰之助の元へ、ある法律事務所から１人の女性弁護士の警護依頼が舞い込みます。担当した案件について逆恨みされ、命を狙われている可能性があるため、厳戒態勢の24時間警護をすることになるのですが…この弁護士、口がたつ上に、自分の考えを曲げない頑固者！　弁護士として行動を制限されることを嫌がり、警護相手としては超最悪！　そもそも辰之助は良く言えばストイック＆真面目なのですが、無骨かつ優秀だからこそ融通が効かず。当然、相性が良いわけもなく…。それなのに、「24時間警護」という任務のために、ひとつ屋根の下で暮らすことに…!?　しかし、四六時中一緒に過ごすうちに気持ちに変化が生じはじめ…!?

Kitazawa Tatsunosuke works as an elite bodyguard for a small bodyguard protection company. He is the ace of the company, with excellent athletic abilities, and is always able to see two or three steps ahead of a situation. When he takes action, he usually manages to stay calm and collected with his judgment. His father, who was a police officer, was stabbed to death.Tatsunosuke, who is currently trying to pursue the killer, receives a request from the law firm to protect a new client. The client happens to be Kishimura Rika, a lawyer who is potentially being targeted due to a grudge against her in regard to a case she was in charge of. Because of this, she has to be under strict security 24 hours a day. Tatsunosuke, who is serious and stoic in nature, is largely inflexible and, naturally, not a good match for Rika, who hates being restricted. However, as they start to live together, their feelings toward each other begin to change.