Quick answer — 22/7 performed 2 anime themes, including "Muzui" from 22/7 (nanabun no nijyuuni), "Sora no Emerald" from 22/7 (nanabun no nijyuuni).
22/7 performed the anime theme songs "Muzui" (22/7 (nanabun no nijyuuni)), "Sora no Emerald" (22/7 (nanabun no nijyuuni)).
22/7's first listed anime theme is "Muzui", the opening of 22/7 (nanabun no nijyuuni).