H1-KEY released the video for 여름이었다 on their own YouTube channel in June 2025, alongside their fourth mini album Lovestruck. The title is worth pausing on before anything else, because it does something English song titles almost never do.

A title that is a finished sentence

여름이었다 means roughly “it was summer”. It is not a noun phrase but a complete Korean sentence: 여름, summer, followed by 이었다, the past form of the copula in its plain declarative ending. That -다 ending belongs to the written register — the form used in novels, diaries and narration — rather than to speech, where a person would say 여름이었어요 instead. Korean titles use it frequently, because it lets a title read as a line of prose while remaining grammatically complete. English has no tidy equivalent, which is why translations of such titles tend to arrive as clauses.

About this release

여름이었다 comes from Lovestruck, H1-KEY’s fourth mini album, with the release time given in the description as 26 June 2025, 6pm KST. The official text names no producer or featured artist. The copyright line reads simply H1-KEY, and the sign-off tags two accounts: the group’s own, and GLG, the agency they record under.

Watching from outside Korea

Romanisations of the title vary, so searches in Latin script can come up short. The description supplies the alternatives worth copying instead: 여름이었다 for the song, and 하이키 and ハイキー for the group’s Korean and Japanese names.

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