Proof

"Proof" is a song by MELL that served as the first ending theme for Hayate no Gotoku! (Hayate the Combat Butler), the television anime produced by SynergySP.

Released on May 30, 2007 as MELL's third single, it appeared on the single Proof / no vain alongside the B-side "no vain" and instrumental versions of both tracks. The release reached No. 18 on the Oricon weekly singles chart and remained on the chart for four weeks.