Nice chapter. Saitou should've told Akane he was doing some work for his aunt in the beginning to avoid the issue. He could've left it at that without going into detail that he was trying to earn money to buy her the ring. I'm glad things worked out in the end.
So happy to see them finally get married. Reading these stories for the past few years really make you think they are real actual people who you are witnessing live out their normal daily lives. I will miss this whenever it does end in the future.
I doubt she will ever see him as anything more than a little brother due to age gap and knowing him since he was a kid. I wouldn't expect any romantic progress in a harem manga anyway.