Naisho no Tsubomi (ないしょのつぼみ, lit. Secret Tsubomi) is a Japanese slice of life romance shōjo manga series authored by Yū Yabūchi, and published by Shogakukan. 8 volumes were released in Japan, the last on April 27, 2012. An OVA anime for the series was released on April 24, 2008. A second OVA episode was released in June, 2008. The series received the 2009 Shogakukan Manga Award for children's manga. It was published in French by Delcourt. Sentai Filmworks released the OVA in North America in January 2018. Source: Wikipedia (en)