21 Days Theory is a special miniseries in Thailand. It is a BL story about two guys in their high school years as they enter a bet that soon became them falling in love with each other. It is something that we have seen so much of already but what I think is the strength of this BL is that they only have four episodes so they did not have to add so many details in the story that will just confuse the viewers. My usual problems with Thai BL is that they are adding to many things in the story that it can easily get confusing but 21 Days Theory did not have that because it is representing a BL story in a much shorter period. There are three love teams here but the main character is of the same sex while the other two are of the opposite sex. They did not have to overly complicate the love stories due to the runtime which became their strongest suite here. They are not actually bad because of it. Instead, they just used it to show the theory and worked on the main relationship instead. Luckily, it worked. I like where they went with the story and I like that they are just giving us a cute and innocent couple. It is always nice to see that. Q and X are actually very fun to look at. Yes, the acting is not the greatest in the entire cast but I think it is enough to really watch them all and enjoy the experience.