"Renai Circulation" is a song from the anime series "Bakemonogatari". It is the fourth opening theme of the series and is performed by the Japanese voice actress, Kana Hanazawa, who also voices the character that the song is associated with, Nadeko Sengoku.

The song is known for its catchy and upbeat melody, with playful lyrics that describe Nadeko's feelings towards the protagonist of the series, Koyomi Araragi. The opening sequence features Nadeko dancing and singing along to the song while surrounded by various scenes from the series.

The lyrics of "Renai Circulation" are written in Japanese and can be translated to English as follows:

"Love circulation, I'm starting it

My heart, heart beats so fast

I'm becoming one with you

Hey, let's fall in love, don't wait!

Love, I'm always daydreaming

But I want to make them come true

Hurry, hurry, let's kiss

Hey, let's fall in love, don't wait!

I can't take it anymore, the heat of love

My heart, heart beats so fast

I want to give you all of me

Hey, let's fall in love, don't wait!

It's fine if we're awkward

We'll get used to it soon enough

Just the two of us, we'll find happiness

Hey, let's fall in love, don't wait!

Love circulation, I'm starting it

My heart, heart beats so fast

I'm becoming one with you

Hey, let's fall in love, don't wait!"

Overall, "Renai Circulation" is a beloved anime opening with an infectious melody and cute lyrics that capture the essence of the show's romantic themes. It has become one of the most popular anime songs in recent years and is a favorite among fans of the "Bakemonogatari" series.