金山漁港旁，阿平與爸爸相依為命。小鎮廟會在即，當選爐主的爸爸，煩惱這次能否捕撈到夠大尾的迦納魚，好在廟會上酬神；撿到廢棄吉他的阿平，一心只想著存夠錢，為舊吉他換上新弦。生活總有跌跌撞撞，但只要父子一起漫步向前，合唱一曲〈金多蝦〉，都是醍醐味。以五月天金曲打底，細察少年活力與父親柔情，在溫柔的影像裡，交織出一則溫暖天真的漁村紀事。

Ping finds a guitar with only three strings at the port and tries to fix it by himself. Meanwhile, his father, the rookie temple host, tries to catch a big snapper as an offering to the god.