[Romanized:]

Action
Chain reaction-action
Chain reaction-action

Yasashiku sareru to chotto
Yasashiku naru no
Fuan na me wo sareru to (sareru to)
Fuan ni naru no
Dandan you're loving me
Dandan I'm loving you
Rensa shiteku kanjou no rarii

Ichi tasu ichi ga ni ni naru kankei
Nanka ja manzoku dekinai dakara
Toushindai yori choppiri ooki na
Ai tewatashite kakezan chuu

Baby ding dong hirogaru chain reaction
Uketotta ai de ch-changing my mind
Kara sashidasu ai de ch-changing your mind
Ai ga ai wo yobu chain reaction

Sunao na omoi wo kiku to
Sunao ni naru no
Kakehiki wa shinaide
Zuru kashigoku nacchau
Dandan you're loving me
Dandan I'm loving you
Eien no kanjou no rarii

Itsuka sekai mo kaete shimau wa
Anata no haato ga zero janai nara
Toushindai yori choppiri ooki na
Ai riree shite kakezan chuu

Baby ding dong hirogaru chain reaction
Uketotta ai de ch-changing my mind
Kara sashidasu ai de ch-changing your mind
Ai ga ai wo yobu chain reaction

Oh oh, chain reaction, oh oh

Tebanasu yuuki no nai (oh baby)
Semai kokoro ni (are you ready?)
Shimaeru saizu no shiawase wa chiisai
Hito kara hito e
Love to iu na no virus ga
Densen shite all over the world
Sou hora hito kara hito
Kara hito kara hito e

Baby ding dong hirogaru chain reaction
Uketotta ai de ch-changing my mind
Kara sashidasu ai de ch-changing your mind
Ai ga ai wo yobu chain reaction

Chain reaction (yobu chain reaction)
Chain reaction (yobu chain reaction)
Chain reaction (yobu chain reaction)
Chain reaction (yobu chain reaction)
Chain reaction (yobu chain reaction)
Chain reaction (yobu chain reaction)
Chain reaction (yobu chain reaction)

[Japanese:]

Action
Chain reaction-action
Chain reaction-action

優しくされるとちょっと
優しくなるの
不安な目をされると (されると)
不安になるの
段々 you're loving me
段々 I'm loving you
連鎖してく感情のラリー

1 1が2になる関係
なんかじゃ満足できないだから
等身大よりちょっぴり大きな
愛手渡して掛け算中

Baby ding dong 広がる chain reaction
受け取った愛で ch-changing my mind
から差し出す愛で ch-changing your mind
愛が愛を呼ぶ chain reaction

素直な想いを聞くと
素直になるの
駆け引きはしないで
ずる賢くなっちゃう
段々 you're loving me
段々 I'm loving you
永遠の感情のラリー

いつか世界も変えてしまうわ
あなたのハートが０じゃないなら
等身大よりちょっぴり大きな
愛リレーして掛け算中

Baby ding dong 広がる chain reaction
受け取った愛で ch-changing my mind
から差し出す愛で ch-changing your mind
愛が愛を呼ぶ chain reaction

Oh oh, chain reaction, oh oh

手放す勇気のない (oh baby)
せまいココロに (are you ready?)
仕舞えるサイズのシアワセは小さい
人から人ヘ
Love という名の virus が
伝染して all over the world
そうほら人から人
から人から人ヘ

Baby ding dong 広がる chain reaction
受け取った愛で ch-changing my mind
から差し出す愛で ch-changing your mind
愛が愛を呼ぶ chain reaction

Chain reaction (呼ぶ chain reaction)
Chain reaction (呼ぶ chain reaction)
Chain reaction (呼ぶ chain reaction)
Chain reaction (呼ぶ chain reaction)
Chain reaction (呼ぶ chain reaction)
Chain reaction (呼ぶ chain reaction)
Chain reaction (呼ぶ chain reaction)

[English translation:]

Action
Chain reaction-action
Chain reaction-action

If you're treated kindly
Will you become a little kinder?
If you're looked at with worried eyes
Will you become worried?
Gradually you're loving me
Gradually I'm loving you
Chaining together a rally of emotions

With a 1 1 equals 2 relationship
I can't be satisfied, so
To a love that's a little larger than life
Surrender when it's multiplying

Baby ding dong, the spreading chain reaction
Changing my mind with the love I received
Changing your mind from the love I present
Love calls out to love, it's a chain reaction

If asked for your honest feelings
Will you be honest?
Don't play games
You'll just become sly
Gradually you're loving me
Gradually I'm loving you
A rally of eternal emotions

Someday the world will also change
If your heart isn't zero
To a love that's a little larger than life
Relay when it's multiplying

Baby ding dong, the spreading chain reaction
Changing my mind with the love I received
Changing your mind from the love I present
Love calls out to love, it's a chain reaction

Oh oh, chain reaction, oh oh

Let go of the cowardice (oh baby)
Within the confined heart (are you ready?)
The size of happiness that can end is small
From person to person
The virus called love
Is infecting all over the world
So look, from person to person
To person to person

Baby ding dong, the spreading chain reaction
Changing my mind with the love I received
Changing your mind from the love I present
Love calls out to love, it's a chain reaction

Chain reaction (calling out, chain reaction)
Chain reaction (calling out, chain reaction)
Chain reaction (calling out, chain reaction)
Chain reaction (calling out, chain reaction)
Chain reaction (calling out, chain reaction)
Chain reaction (calling out, chain reaction)
Chain reaction (calling out, chain reaction)