Quick answer — Aya Hirano performed 1 anime theme, including "Hare Hare Yukai" from The Melancholy of Haruhi Suzumiya.
Aya Hirano performed the anime theme songs "Hare Hare Yukai" (The Melancholy of Haruhi Suzumiya).
Aya Hirano's first listed anime theme is "Hare Hare Yukai", the ending of The Melancholy of Haruhi Suzumiya.