According to T.S. Eliot, April is the cruelest month. But in Japan May ushers in some pretty heavy blues, too. The dual combination of haru no megumi (春の恵み, spring blessings) and haru no utsu (春の鬱, spring depression) makes for a challenging 31 days.
That February is also depressing is a no-brainer. From start to finish, it's an awful time, but at least you get to stay in bed and nurse your infuru (インフル, influenza), which sounds like a bum deal but believe me, a chunk of guilt-free kyūkeijikan (休憩時間, rest time) just does not happen anywhere else on the Japanese calendar.
However, go-gatsu (五月, May), also known as satsuki, is a beauty. Even in the tokai no sabaku (都会の砂漠, urban desert) that is Tokyo, we get to savor the shinryoku (新緑, new leaves) against a gorgeous blue satsukibare no sora (五月晴れの空, clear May sky), the likes of which come around only several days a year with flowers blooming in even the dingiest of city alleyways.