here's my honest thought, no of the girls are worth it. You'll probably think am crazy but here's my reasoning:
Shiori : had feelings for Jirou so long, she now attempts to make moves to reveal it because he is becoming closer and closer to Akari, she'd probably stick to the status quo if, akari never came, she has an inkling he feels the same, she refuses to actually try and when she does, she gets scared and falls back to "just childhood friends" hell she expects him to just think of her(this very chapter), this girl honestly is a coward (as much as Jirou) who should lose since she only winning because someone else mentioned nostalgia.
Akari: She pisses me off more, Akari has developed feelings for Jirou over time and now "all in" since she herself is a coward and only confessed to the other character(can't remember his name right now) and failed. Well if she confessed this entire series would be over but she understands he likes Shiori and also she has seen inklings herself that it may be mutual, instead of being honest (which she herself has had chances too), the beach scene where she wanted to show the swimsuit "just to him" or all the home interactions when they embrace one another, she has a chance and she would most likely win however a tsundere being the worthless dere they are, bitch out at the last second or every given chance they get, it's probably not until Shiori gets more aggressive is she going to make any move.
Jirou: Now this motherfucker, THIS DENSE ASS, DUMB ASS COWARD ASS MOTHERFUCKER!. Jirou I understand you love Shiroi and I understand you've grown to be atleast infatured with Akari but all these signs, to begin with this entire manga is full of cowards it appears the last title attach to the end of the manga should be cowards, he has kissed Shori TWICE and yet, he still refuses to ask her if she may have romatic feelings for him, he even question a deep kiss, if it wasn't, his denseness maybe the series would already be over, then there's Akari, even the most inexperience of virgins should see signs of "wait maybe she's interested in me", not only has she embrace you several times, she has gotten angry with you because you used her last name, she even showed a bikini while blushing saying she had to show it "just to you" yet, this dense blackhole of a useless otaku, refuses to see the writing on the walls, hey it's okay to fall in love with someone else over time, you ain't dating Shori, hell during your confession she technically turned you down BUT even then do both girls have to write I LOVE YOU on a bat and beat you over the head before you realize, what's going on ?