Ko
(
コ
)
tsu
(
ツ
)
Ko
(
コ
)
tsu
(
ツ
)
App Store
Google Play
Vocabulary
Non-JLPT
Day 63
難題
New
難題
難題
なんだい
difficult problem
noun
Sino-Japanese
Lv.4
Again
1
Hard
2
Good
3
Easy
4
Previous word
Space flip · 1–4 grade · ← → move
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