Yaoi finatics will always find yaoi even in places where there isn't any. A good friendship between males? Obviously they love each other. Two characters hate each other's guts? They're obviously fucking behind the scenes. A character looks at another character a certain way. He obviously loves him just confess already! Don't worry about it some people just have hardcore imaginations I mean I wouldn't be against some of those fantasies being real.
Yaoi Logic (≧∀≦)
There is (probably) some fan service but there is definitely no canon yaoi action going on.
I've only read the first two doulou dalu series so far so I can only take a guess about the fanservice but the other two were so painfully hetero-normative that this one is definitely going to be the same.
(If you were a man I'd marry you, I wish you were a girl, in our next lives I hope that I'll be born as a male so we can get married, etc.)
See comments saying it has some yaoi vibe in it.