Search Everything

Login

Send feeback or report a bug here

Send feeback or report a bug here

poster
poster

The 21-Day Theory

1 Season
4 episodes
Ended
9.0

Watch Trailer

Using the 21-Day Theory, a determined woman pursues a wealthy man to prove he's straight—but the truth defies her expectations.

Similar TV Shows

Cam Boy

Cam Boy

2021

4.0

TV show
Loving, Never Forgetting

Loving, Never Forgetting

2014

7.3

TV show
Step By Step

Step By Step

2023

6.4

TV show
I Feel You Linger in the Air

I Feel You Linger in the Air

2023

9.3

TV show
Hard Love Mission

Hard Love Mission

2022

6.4

TV show
Couple or Not

Couple or Not

2023

0.0

TV show
Gravitation

Gravitation

2000

6.4

TV show
Plerng Sanaeha

Plerng Sanaeha

2019

8.0

TV show
Mary & George

Mary & George

2024

7.2

TV show
Bali Hai

Bali Hai

2025

1.0

TV show
Cucumber

Cucumber

2015

7.3

TV show
Forevermore

Forevermore

2014

7.2

TV show
Return of Bok Dan Ji

Return of Bok Dan Ji

2017

0.0

TV show
The Return of Hwang Geum-bok

The Return of Hwang Geum-bok

2015

5.0

TV show
12 días que estremecieron Chile

12 días que estremecieron Chile

2011

2.0

TV show
Please Teach Me

Please Teach Me

2024

0.0

TV show
Wishing Upon the Shooting Stars

Wishing Upon the Shooting Stars

0.0

TV show
The Helicopter Heist

The Helicopter Heist

2024

6.9

TV show
Brilliant Legacy

Brilliant Legacy

2009

7.4

TV show
A Very Royal Scandal

A Very Royal Scandal

2024

6.6

TV show

Recommendation

21 Days Theory

21 Days Theory

2022

7.1

TV show
Stranger Things

Stranger Things

2016

8.6

TV show
Brooklyn Nine-Nine

Brooklyn Nine-Nine

2013

8.2

TV show
Breaking Bad

Breaking Bad

2008

8.9

TV show
Death Note

Death Note

2006

8.6

TV show
CSI: Crime Scene Investigation

CSI: Crime Scene Investigation

2000

7.6

TV show
The Lord of the Rings: The Rings of Power

The Lord of the Rings: The Rings of Power

2022

7.3

TV show
Two and a Half Men

Two and a Half Men

2003

7.4

TV show
Wednesday

Wednesday

2022

8.4

TV show
All of Us Are Dead

All of Us Are Dead

2022

8.3

TV show
The Good Doctor

The Good Doctor

2017

8.5

TV show
Money Heist

Money Heist

2017

8.2

TV show
Doctor Who

Doctor Who

2005

7.6

TV show
Squid Game

Squid Game

2021

7.9

TV show
Young Sheldon

Young Sheldon

2017

8.0

TV show
Alien: Earth

Alien: Earth

2025

7.4

TV show
Friends

Friends

1994

8.4

TV show
Sweet Home

Sweet Home

2020

8.3

TV show
Adolescence

Adolescence

2025

7.8

TV show
Moonlighting

Moonlighting

1985

7.5

TV show