Senyu (戦勇。, Senyū) is a Japanese web manga series written and illustrated by Robinson Haruhara [ja].

A print version was published in Shueisha's shōnen manga magazine Jump Square from May 2012 to April 2013, with its chapters collected in two tankōbon.

A millennium ago, the Demon King wreaked havoc in the human realm, but was sealed by the legendary Hero Creasion.

The series starts almost exclusively comedic, with episodic gags mainly involving Alba's bad luck and Ross's abuses.

The world's past and Creasion's origins are explored in the second part, culminating in the supposed defeat of the story's main antagonist, the first Demon King.

The fourth volume explores Elf's past and his complex involvement with existence, concluding Senyu's main storyline.

[14] Haruhara published a print version of the series in Shueisha's shōnen manga magazine Jump Square from May 2, 2012,[15][16] to April 4, 2013.