小學時代的兩津勘吉（香取慎吾飾）被同學們戲稱「說謊阿兩」。阿兩來不及解釋自己曾說過的誇張故事

　　故事发生在位于葛饰区龟有公园前的派出所之中，两津勘吉是负责此区域的一名警察。两津勘吉在行业内的口碑十分糟糕，这个对金钱有着超乎常人的执着的男人，拥有着超强的生命力和行动力，上班的时候插科打诨浑水摸鱼，下班后唯一的兴趣爱好便是打小钢珠。中川圭一表面看来只是一名普通的巡查，其另一重身份系中川财阀社长，年纪轻轻却富可敌国。样貌英俊温文尔雅的中川是女警们心目中的白马王子，但中川却对粗鲁的两津勘吉“情有独钟”。此外还有活泼可爱的秋本丽子，在两人的协助之下，两津勘吉以自己独特的方式保护着这片挚爱的土地。

Ryotsu Kankichi, nicknamed Ryo-san, is a senior patrol officer working at the Kamearikoen-mae police box at Katsushika. Because of his daring, hearty, unconventional, haughty and overbearing personality, he is called "letter of apology Ryo-san" and everything he does is nonsense. There is endless trouble wherever Ryo-san goes. He makes Akimoto Catherine Reiko and Nakagawa Keiichi, his juniors from the same police box, fearful. His superior, Ohara-buchou, lives each day as if lightning will strike as a fearless power keeps going off day after day. He definitely doesn't have poor ability as a "patrolman of the police box" in the mediation of quarrels, taking care of New Year's gifts or discussion of neighbourhood problems but he has a bad temper, gets tired of things easily and detests working. He is a police officer but because he loves gambling, he spends his money recklessly and in addition to this mess, is heavily in debt. He has a weakness for get rich quick schemes, and has a manic desire and knowledge to have fun and make money. Then one day, Ryo-san receives a tempting proposition...