Like jiyuu na kimi ga suki dakedo
Hottokaretara sore wa sore de samishi

Love kami o kirisugichatta mitai
Hontou gara janai soko wa demo kawaii deshou?

Sotto me o tojita mama yubisaki de sagashitai
Kagi to kagiana mitai
Sore de kono tsugi no teiku watashi ni makasete
Natsu o purodyuusu shite ageru futari kiri de

You're the first one (Yeah!) ni yattekimashita mabushii SEASON
Atsui taiyou (Yeah!) koi suru kimochi motto moriagatte yukou
Kotae nara "YES" (Yeah!) dakedo kantan da tte omowaretakunai
Hajimete wa (hajimete wa) ichido dake taisetsu ni To You

Source: https://www.animethemesongs.com/hajimete-no-gal/hajimete-no-season