I dunno what significance Flowers for Algernon have, but it's the only place the phrase γΎγγγγ occurs I could find, so it seems pretty likely it's an actual reference.
Sudden BoomSincerely, for you
It's also the Japanese title of both theatrical adaptations of Flowers for AlgernonMokou!I brought you a present!Love*creak* *creak* *creak*Mokou? What's the matter?