i am too invested on 1st couple

since this is the first time i read such a funny fluffy chemistry from a couple.. the first story makes me laugh a lot in a good way to the point i forgot it was yaoi story ... when i saw season 2 is a completely different story i am hugely dissapointed.. my question is why? i understand if the second couple is someone that close to the main couple like the sister and his secretary for example.. but this is completely unrelated to the main couple it threw me off... meeh... i probably will read the s02 if i want to and if i remember