There's not much of establishing MC and ML's relationship just yet. However, I find the initial setup of their relationship (as strangers who get along) refreshing and endearing since most stories usually have MC already knowing ML via isekai knowledge or MC forming quickly a marriage of convenience contract with ML to escape her awful fiancé. Here, MC doesn't know him and ML doesn't know her, but she's not forcing ML to pair up with her (even though she really needs it) like most Esper MLs do. She's just winning him over with flowers because she'd like him to have a good impression of her and she tries to look after him. And I sense that ML finds her endearing as he indulges her by making small talk with her, teasing her a bit, and accepting her weirdly-arranged flower bouquet each time lmao. I enjoy them getting to know each other as they slowly become closer.

There's a 2nd ML who's a S-ranked Guide (he's the leader of all Guides and owns a facility) and is like a cold-type, bitter ex even though he and MC never got together.

It's likely the heavy miscommunication and how 2nd ML expresses himself in that cold, overbearing, indirectly affectionate ML way (do you really expect MC to be a mind reader and pick up on the little clues that most people wouldn't notice with that cold face of yours looking always pissed off, bruh?) which is why he rubs MC the wrong way that they've grown apart before he could even become close to her in the romantic way besides their compatibility not being good.