This might be an unpopular opinion, but I think Ajisai x Renako is the best pairing in the series. Nobody seems to like this couple because they think their relationship is unhealthy, but that's exactly what makes it interesting. Unlike say Mai x Renako or Mai x Ajisai they're not a perfect couple devoid of any issues. Renako still idolizes Ajisai to the point of putting her above herself & Ajisai is desperate to feel as much of Renako's love that Mai has. Unlike the other 2 pairings, they're actually feel like a real relationship becauseit's not perfect & they have problems they need to work together to fix.