[REACTION] BE:FIRST - 'Mainstream' (MV + Dance Practice) | This is exciting.

REACTION TO no tickets for haters by S2

BE:FIRST "Boom Boom Back" (Official Music Video) | Couples Reaction!

[REACTION] FINALLY!!!!!!! Introduction to BEFIRST

BE:FIRST / Mainstream & Masterplan -Music Video- | REACTION

I Watched BE:FIRST X ATEEZ / Hush-Hush -Music Video- 10 Times and This Is What I Found

ZorDon Reacts to "BE:FIRST / Masterplan -Dance Practice-" | Fandom Fridays

BE:FIRST X ATEEZ - REACCION A "HUSH - HUSH" ( MADRE MÍA QUE GOZADA!)

BE:FIRST - 'Mainstream' MV | REACTION

[REACTION] BE:FIRST - Smile Again / THE FIRST TAKE

FIRST TIME REACTING TO BE:FIRST - 'Mainstream' | -Music Video-

DANCER REACTS TO BE:FIRST / Mainstream MUSIC VIDEO & DANCE PRACTICE

【神回】遂にGrow UpがYouTubeに！！BE:FIRSTの圧倒的な強みは全員の◯◯？！（BE:FIRST / Grow Up -with Apartment Band ver.-）【歌声分析】

FAILED FILM STUDENT REACTS TO: SKZ - CHK CHK BOOM

FIRE!! 🔥 BE:FIRST Mainstream MV + Dance Performance REACTION

BE:FIRST x ATEEZ | Hush-Hush MV REACTION

【BE:FIRST】【オタクシンガーリアクション】「Grow Up」セッションを初めて見てみたら良すぎて地面割れた｜BE:FIRST「Grow Up」Apartment Band ver.リアクション

BE:FIRST / Boom Boom Back -Music Video-

Reacting to BE:FIRST - "Sailing" (One Piece Ending) & "Metamorphose" Dance Practice!

BE:FIRST - Masterplan MV - REACTION

BE:FIRST X ATEEZ / Hush-Hush -Music Video- | REACTION