Why..

Why.. is the first extended play (EP) by the South Korean boy band BoyNextDoor, released on September 4, 2023, through KOZ Entertainment, three months following the release of the group's debut single album Who! (2023). The EP consists of six tracks, including the three singles from Who!, and the lead single "But Sometimes (뭣 갈아)".

Background
BoyNextDoor debuted in May 2023 with the release of their debut single album Who!, which was preceded by the release of music videos for the singles "But I Like You", "One and Only" and "Serenade". Upon debut, the songs for both Who! and Why.. have been completed. The physical CDs of the single album contained a 13-second long hidden track which hinted at the group's next release. KOZ Entertainment announced on July 13, 2023, that the group would be releasing new music in September.

Music and lyrics
Why.. has a runtime of 16 minutes and 45 seconds and consists of six tracks. Members Jaehyun, Taesan, and Woonhak, and the label's founder, Zico, participated in writing the songs for the EP.

The songs written for the EP explore the themes of "experiencing a breakup for the first time", serving as the culmination of the three tracks from the group's previous release Who!, which were collectively described as being about the "fresh excitement of boys who fell in love with their first love". In a showcase for the EP ahead of its release, Riwoo explained "We prepared both albums together and we treat them as one [big] album". The songs written for the EP features frank lyrics; Woonhak stated in an interview with The Korea Herald that they "used the daily language and gestures of the members in the lyrics", aiming to have the songs to "sound like talking to a friend".

Songs
The EP reprises "But I Like You", "One and Only", and "Serenade", as its first three tracks. The fifth track, "But Sometimes", serves as the EP's lead single. Member Taesan described the track as a "breakup song that directly expresses the complex feelings about the first love that ended in vain". Leader Jaehyun added that the track "conveys the complex emotions of your first love that ultimately didn't work out", aiming to capture the "raw emotion" that arises from such situation. The closing track "ABCDLove" discusses the themes surrounding feelings from love to separation and afterwards.

Release and promotion
Why.. was released on September 4, 2023. The release of the EP was accompanied by the television special BoyNextDoor 2Night, which aired on Mnet and M2.

Marketing
On August 8, 2023, the group released a teaser image depicting a carousel ride in black and white to announce Why.., the group's first extended play. The announcement of the EP was accompanied by the release of a promotion schedule patterned after the ending credits of a movie. Teaser films for the EP were released on August 14. The teasers depict the members' "emotional changes in the start and end of a relationship". The track list of the EP was revealed on August 17. Concept photos depicting the members were released on August 20. A "track spoiler" previewing snippets of the EP's tracks was released online on August 27.

Music videos
A music video for the lead single, "But Sometimes", was released in conjunction with the album's release. The video depicts the members being unable to "maturely accept the breakup they experience for the first time". The music video sees the neighborhood in the music video for "Serenade" burn to ruin, with the members sinking in water.

Commercial performance
On August 12, 2023, YG Plus, a distributor of the extended play, reported that the pre-orders for the EP exceeded 300,000 pre-orders within three days.