Wrestle! The Under Ground (レッする! ジ・アンダーグラウンド) is a 4 volume manga series by Buredo that was serialized in Comic Valkyrie.
The organization known as “Gigant” has sent one of their best men to kill a cute young high school girl. However, the assassin seems reluctant… Why did he get those strange orders to execute after the murder? What’s the secret behind that girl?