close friend, bosom buddy / crony, chum

刹那: instant, moment

a female given name

切ない: painful, trying or oppressive

roughly 0.11 seconds, defined as 1/65ᵗʰ of a 弾指 (danshi), where a danshi is 1/12,000ᵗʰ of a day or 7.2 seconds / 0.002 seconds, defined as 1/60ᵗʰ of a 念 (nen), where a nen is 1/60ᵗʰ of a 弾指 (danshi)

(chiefly women's speech) first person singular pronoun: I, me

(polite) first-person singular pronoun: I, me

a personal or private matter / (by extension) selfishness

(formal) first-person singular pronoun: I, me

personal, private / secret