I do! Do you?

"Fly-By" (stylized as 𝐹𝐿𝒴-𝐵𝒴) is the second Japanese single by Kep1er. It will be released on March 15, 2023 with "I Do! Do You?" serving as the single's title track. "Wa Da Da (Japanese ver.) (IMLAY Remix)" was pre-released on February 15, 2023. "I Do! Do You?" will be pre-released on February 22, 2023. The single comes in twelve versions: Regular, Limited A, Limited B, and 9 individual fanclub versions.