| If -Mata Aetara- | |
| Cover: | IfMataAetara.jpg |
| Border: | yes |
| Caption: | Standard edition/digital download cover |
| Type: | single |
| Artist: | Day6 |
| Album: | Unlock |
| B-Side: | Baby, It's Okay |
| Released: | March 14, 2018 |
| Label: | Warner Music Japan |
| Chronology: | Day6 |
| Prev Title: | I Like You |
| Prev Year: | 2017 |
is a song recorded by South Korean band Day6. The song was released as the group's first Japanese CD single on March 14, 2018, by Warner Music Japan. Ahead of its release, the song was pre-released as a digital single on February 26, 2018. "If -Mata Aetara-" serves as the theme song for the Japanese television drama, Repeat (Unmei wo Kaeru 10 Kagetsu).[1]
The song is in the key of E Major and is 184 beats per minute.
|-! scope="row"| Japan (RIAJ)| | 4,832 |-|}
| Region | Date | Format | Label | Ref. |
|---|---|---|---|---|
| Japan | February 26, 2018 | Digital download (Pre-release) | Warner Music Japan | [4] |
| March 14, 2018 | CD single (Standard edition) | [5] | ||
| CD single/DVD (Limited edition) | [6] | |||
| Digital download | [7] | |||