Particle, emphasizes preceding word or phrase
1. it is ... that ..., precisely, in particular, definitely, for sure, only (when, after, because, etc.)
as こそあれ, こそすれ, こそするが, etc.
2. although, while, it is the case that ... but
after conditional -ba form of verb
3. it is precisely because ... that ..., only because ...
formal or literary term, after -nai stem of verb + ば
4. not at all, not in the slightest, absolutely not, never
くっそ, 苦蘇, こそ, クッソ, コソ
Usually in kana
kousso (African flowering plant, Hagenia abyssinica), kosso, cusso, koso, brayera