Title of the song translates to Let’s Marry by Takuro Yoshida from his 1972 single of the same name

Note: This post is a direct copy/paste from my old blog

僕の髪が肩までのびて
君と同じになったら
約束どおり町の教会で
結婚しようよ MMMM

When my hair grows till my shoulders
Just as long as you
Let’s marry at the town church
Like promised

古いギターをボロンと鳴らそう
白いチャペルが見えたら
仲間を呼んで花をもらおう
結婚しようよ MMMM

Let’s play the old guitar
When the Chapel is visible
Receive flowers from our friends
Let’s marry!

もうすぐ春がペンキを肩に
お花畑の中を散歩にくるよ

When spring comes
Carrying paint on its shoulders
To color the field of flowers

そしたら君は窓をあけて
エクボを見せる僕のために
僕は君をさらいにくるよ
結婚しようよ MMMM

You open the window
And smile with a dimple on your face for me
I am going to come to take you
Let’s marry

雨が上がって雲のきれ間に
お陽様さんが見えたら
ひざっこぞうをたたいてみるよ
結婚しようよ MMMM

When the rain stops
And sun shines through the clouds
That’s when I will come for you
Let’s marry

二人で買った緑のシャツを
僕のおうちのベランダに
並べて干そう
結婚しようよ僕の髪は
もうすぐ肩までとどくよ

The green shirts we bought together
Let’s keep them to dry on the veranda
Of our house
Let’s marry
My hair will soon reach my shoulders