五 five

fifth day of month ★★★★★ FP
五 (five) + 日 (sun, day) = 五日 (fifth day of month)

the fifth day of the month. Also a homonym for 'when,' so that Abbot and Costello routine practically writes itself.

May ★★★★★ KANA
五 (five) + 月 (moon) = 五月 (May)