Weekly Shōnen Sunday
is a Japanese manga series written and illustrated by Shin Takahashi. The manga was serialized in Shogakukan's "Weekly Shōnen Sunday" from September 2002 to March 2004, but Takahashi stopped its serialization and continued releasing the story directly via "tankōbon" volumes. A total of nine "tankōbon" volumes were published from January 2003 to July 2010. A 2-chapter story, titled "Spica", was published in "Weekly Shōnen Sunday" in 2010 and 2013.