The single features participation by members Sho Yonashiro and Ren Kawashiri in writing lyrics and choreography, respectively, for the first time as well as production by Hui from South Korean boy group Pentagon and others.

"[5] Meanwhile, the cover image of the limited edition B gives a glimpse of the adult side of the members wearing clothes from Louis Vuitton's 2020 pre-fall collection titled Arc of Boyhood.

[13] About song "My Friends", Yonashiro stated that he had decided to write the lyrics then consulted it with their production team in South Korea during the recording of Protostar.

[15] The lead track, "Oh-Eh-Oh", is a song that combines EDM, house music, and vocal that reflects the determination to push into the future, creating an overwhelming sense of exhilaration.

Music Champ on August 1,[16] and the appearance of the name of Hui from the South Korean boy group Pentagon on the song credits gathered the public's attention.

[19] It features a fighting scene between the members, acting as high school students, and a mysterious group with Kawashiri playing two roles.

[28][29][30] On September 5, the group performed songs "Go", "So What", and "Oh-Eh-Oh" as the headliner for the 31st Mynavi Tokyo Girls Collection Autumn/Winter 2020, the largest fashion event in Japan, held in Saitama Super Arena and streamed via Line Live.

[36] Upon its release, Stargazer ranked at number one on iTunes's real-time album charts in seven regions in addition to Japan, such as Thailand and Indonesia.

[39] This made JO1 the only artist with two consecutive wins on the chart since their debut single after Hinatazaka46 managed to do so with "Do Re Mi Sol La Si Do" on July 29, 2019.

[40] Subsequently, it ranked third on the monthly chart,[41] and certified platinum by the Recording Industry Association of Japan for shipments of more than 250,000 units.