Once the anime for these series ended, I immediately sought out their mangas to read the continuation of these tales. Unfortunately, neither 'continuation' impressed me much, which means an animated sequel to either show wouldn't make much of a difference.
For Gekkan Shoujo, what you get in the manga is just more of the same. More episodic chapters which could be anywhere chronologically, because none of the initial situations ever change from when they were introduced. Only one new character is introduced, Nozaki's little brother, who is funny but also so absurd that you can't take him (or anyone in this series really) seriously. One of the biggest problems with pure comedy series is that there's no room left for drama because the characters are no longer lifelike enough for their situations/problems to be believable. Supposing one of the main characters suddenly came down with brain cancer and slowly died away in a hospital bed, how could we react to such a scene? With a bunch of comic hijinks and misunderstandings? Would Nozaki turn it into more material for his manga? Would Seo accidentally zap him with a defibrillator? Comedies back themselves into a corner of people being too stupid to live, and then if the situation ever got serious you find immediately how unbearable their character traits really are. It goes from funny to obnoxious at light speed.
As far as the comedy in the future goes, it's still grade A, with very few just straight repeat gags that have already worn out their welcome. But with zero character development, zero relationship development, and zero progress of time, it really feels like you're just walking a treadmill to nowhere with this show. Unless the manga really picks up its pace and tries to resolve its initial dramatic developments, I don't see the point of the anime getting a second season to nowhere.
Ao Haru Ride is even worse. What started off as a pure love story, the development of two character's feelings for each other without any reference to anyone or anything else, immediately after the anime season ends turns into a juvenile and pathetic angsty love triangle where 'the other girl' and 'the other guy' constantly intervene to keep the story going. Even though it's absolutely clear that Kou and Yoshioka only have eyes for each other, somehow the story manages to create intercessor rivals who get in their way and keep them apart. It isn't in Kou's character to randomly start caring about another person's feelings just because they're going through a hard time, and it isn't in Yoshioka's character, who has cherished her love for Kou for the last three years and is finally making a lot of progress, to suddenly give up on him and start going out with a completely new guy she just met, cares nothing for, and has no redeeming traits. It just feels like the author wanted to prolong the series so suddenly took a complete right turn just for the sake of a right turn from all previous story developments. It shouldn't matter that when Yoshioka confesses to Kou, he says he can't go out with her. She's already known that her feelings for him were stronger than his for her from the very beginning. That never stopped her before. She always kept up a strong front and kept trying to show her appeal to him in order to melt his frozen heart, and it had been steadily making progress all this time, to the point that they'd even made out already. To give up at that point is just madness. She's obviously right on the brink of victory. Just a little more patience and a little more appeal would have bagged him for good, but instead she runs away and cheats on him with another guy right after confessing to Kou her supposed 'love.' What a slut.
The Ao Haru Ride manga will at some point get together Kou and Yoshioka and set everything right, but it almost feels too late to salvage the series. It's already been established how fickle these character's feelings are, so even if they do get together they'll probably just break up again later over another stupid thing. Once your relationship is busted once, once you've been cheated on and betrayed once, there's really no trust left in the relationship left over to try it a second time. Yoshioka will surely feel justified somehow or other to betray Kou again in the future. Maybe he'll call her a bad name. Or maybe he won't buy her enough presents for Valentine's or Christmas. Or maybe he won't take her to enough fun places on the weekends. There's always a reason to cheat. Once a girl has justified her treachery once, she is at a point, morally speaking, where anything at all could trigger the reaction again. The best thing for boys to do when they meet a girl who's betrayed her previous lover is to just steer clear. These girls can never be trusted again, and there is no reason to believe she'll be different with the next boy, or the boy after, because she's using the exact same vocabulary, the exact same words and promises, that she previously spoke to the previous boy, so how on Earth can you trust her feelings for you as somehow different from the previous jaunt?
The fact that Kou was 'too slow' to respond to her feelings is absurd. If her feelings for Kou were serious, she would have waited ten years or a hundred years for him, as many years as it took. She would have waited her whole damn life if he was truly the boy she loved. Nor was the situation anything like the way she painted it. She wasn't just banging her head against a stone wall. He wasn't just coldly rebuffing her at every moment and keeping her at arm's length. For God's sake, he had already trapped her in a classroom and kissed her three times in a row, telling her she could stop it whenever she wanted, and she had already closed her eyes and stayed for more. If this is 'too slow' a romantic development pace for her, then what exactly would be too fast? For this imaginary crime of being 'too slow,' this slut went off with another guy and started kissing her 'boyfriend' she doesn't even have any feelings for. Now when Kou is ready to love her, she flaunts her new boytoy and says it's too late and sticks out her tongue bragging like a 2 year old. God. The boytoy can keep her. Who would want such an immature, impatient, volatile, fickle, and ultimately slutty cheating traitor? Boytoy can have her and good riddance. Another bullet dodged. A mistake averted. Count your blessings and go thank God she left you early when it still hurt the least. Other girls than Yoshioka have liked Kou in the past and in the present. There will be other girls in the future as well. All of whom are more reliable than she will ever be. To hell with her and this manga as a whole.
Which leaves the anime in a curious place. Just like the Usagi Drop anime. If it stops where it does, it will stay a good story with a promising imaginary future where everyone lives happily ever after. If it continues to adapt its manga source, though, it would quickly plummet into disaster and stupidity. In the case of an anime cutting off a source right before it becomes bad, should the anime be judged independently of the known bad source? I don't think so. An anime with a known promising future in its source material has to reflect better on the anime than an anime with a known disastrous future in its source material, because the future impacts our views of what happened before. If the past and the future don't connect coherently then both the past and the future halves of the story are bad, not just the future alone. It's bad writing from start to end if the beginning leads right into the plummeting waterfall of despair that is the ending. There's no way to salvage a beginning which you know was set up for such a bad ending, and part of the overall warped monstrosity as a whole. The only time you can really forgive a bad ending is if the original author dies and someone else writes the rest of the material, like in the case of Wheel of Time. Otherwise, the whole story must be judged together to have fallen flat, from beginning to end, because that was the entirety of the authorial vision.
Ao Haru Ride follows a lot of conventional shoujo tropes, none of which are good. The 'nice guy' who pesters a girl to love him even when she's rejected him multiple times. The 'rapist' who sexually harasses/molests a girl first and then asks for permission later. The 'other woman' who tries to steal the guy away even though he's already your marked property, etc. I don't know what you can do to improve shoujo stories. It feels like they are so stuck in the same rut that every shoujo comic is an exact replica of every other shoujo comic, and they all make the exact same mistakes, because apparently the girl readers who buy this stuff eat it up and love this stuff. So long as girls have bad taste in art, more of these travesties will continue to be churned out like a car manufacturing plant, and this doesn't look like it's going to change for centuries, because female bad taste in art goes down to a genetic level. The best shoujo stories avoid romance as much as possible, like Aisheteru ze Baby, which is about raising an abandoned child, or Sailor Moon, which is about fighting galactic menaces, or Card Captor Sakura, which is about collecting magic cards. Maria-sama ga Miteru has an admirable solution by just plopping all the girls into an all-girls school where contact with men is minimized. Chihayafuru keeps it centered on Karuta. 12 Kingdoms, Gakuen Alice and Kobato include a bunch of fantasy elements and keep the romance backstage. Straight shoujo romance stories basically just comes down to Kimi ni Todoke and Ao Haru Ride. In both cases, the anime is better than the manga, because after the anime ends the manga just keeps going downhill. In both cases, the series just don't live up to their potential because of the bad decisions the characters ultimately make somewhere down the line. Waiting for a good shoujo romance story is a little like waiting for Godot. Ao Haru Ride and Kimi ni Todoke are the best of a bad lot, but that's just not saying much in the end. The best romance stories are still written by men, for men, like Clannad, Cross Game, Kanon, Da Capo, Toradora, Bakuman, Basilisk, Major, Oreimo, and on and on and on. As the Prince of Tennis would say -- mada mada dane.