Zassou no Uta (雑草のうた; Song of Weeds) is Buono!'s 11th single. It is their first single released on the zetima label. It was released on February 2, 2011, in both limited and regular editions, the limited coming with a bonus DVD. The single V was released on February 23, 2011. This was also the first Buono! single that was not featured in the anime Shugo Chara!. The single reached #9 on the Oricon charts and charted for three weeks, selling 14,794 copies. The single V reached #17 on the Oricon charts and charted for one week, selling 1,795 copies.