Appears on releases
| # | Title | Length | Track artist | Release title | Country/Date | ||||
|---|---|---|---|---|---|---|---|---|---|
| Official | |||||||||
| 1.1 | コイイロ | 4:31 | AZU | コイイロ |
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| 1.8 | コイイロ | 4:33 | AZU | AS ONE |
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| 2.2 | コイイロ | 4:31 | AZU | BEST (初回生産限定盤) |
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| 1.3 | コイイロ | 4:30 | AZU | SINGLE BEST ＋ 〜10th Anniversary〜 |
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| 1.3 | コイイロ | 4:30 | AZU | SINGLE BEST ＋ 〜10th Anniversary〜 |
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| Pseudo-Release | |||||||||
| 1.8 | Koiiro | 4:33 | AZU | AS ONE (romaji) | |||||