Audience-Alienating Premise: The game itself isn't bad and has a pretty compelling story, but what turns people off is the fact that teaching each girl new skills and the entire "motivation" mechanic involves beating and torturing the girls in a way intended to be titillating.
The censoring of the CGs for the motivation mechanics. Some feel that fans should be lucky that the game was localized at all and that it really hasn't been as horribly censored as many believe it was. Others believe that the game was marketed to specific type of demographic and thus there was no point in it being censored in the first place.
Complacent Gaming Syndrome: Whenever players choose which party members will be on their starting team, 90% of the time, Ran will be on that team. She is the only member of the party who possesses a full team Revive that also acts as a healing skill for those who haven't be knocked out and the Guard skill that greatly increases defense of all party members and always procs whenever an enemy is preparing a particularly powerful attack. She also has a counter attack that draws enemy fire to her before returning with a rather powerful blow, and thanks to her beefy defenses, she rarely has to worried about being killed. Finally, either at the end of the main game or the post game (Depending on when you chose to Knight her), she gains immunity to status effects and the Knight's Guard skill, which act similar to the Guard skill except it makes all party members invincible for two turns.
Fridge Horror: The realization when entering post-game that, upon earning the normal endings prior, Miu and Himekami were basically sent to an eternity of damnation without being given another chance at the Reformation program.
Alice. Learn all of her skills, boost her magic attack, use her Charge ability and unleash her most powerful spell. She'll easily do upwards of 15,000 damage whereas most others can only manage to, at most, do half of that on their own. Knight her and she'll rip any semblance of difficulty in half.
Miu has subpar damage output but has incredible defense and the best support skills available, including a chance to auto-revive fallen allies and making everyone's abilities cost no MP for the next few turns.
Tomoe's instant death skills, because, unlike most examples, they work. Even in the rare occasion it doesn't kill, it still deals a respectable amount of damage.
Genius Bonus: The first three blocks follow the description of hell outlined in Dante's Inferno. Shin picks up on this too.
Good Bad Bugs: It's possible to instantly kill anything by using Miu's first bond skill and then using Shin's Operation End without changing any of the four active girls.
Moe: Alice is a small, cute, shy girl who really wants to be loved.
The Motivation mini-games. Even after disregarding its Audience-Alienating Premise and the Broken Base over its censorship, many didn't like that they were only way to learn new moves and that they required more money to play as the rank increases. This required players to grind extensively for these mini-games, most of which aren't fun to play due to the mandatory use of both of the Playstation Vita's touchscreens. It doesn't help that it leads to some major Gameplay and Story Segregation with the main character as his Nice Guy persona and his willingness to hear out the girls doesn't mesh well with the kinky torture he places the girls in.
Not being able to choose attacks. While the game is balanced around it and being able to use Alice's or Tomoe's moves at will would remove any pretense of challenge, it's frustrating when fighting a more difficult foe and being unable to use moves that would be useful. It's particularly painful because Oreshika: Tainted Bloodlines has the same mechanic, but lets you override suggested moves for a small penalty.
That One Attack: Two, actually. Both on the final boss! First is Zone Bind, which will always be one of the two attacks the boss uses every turn during the first phase and still extremely common in the second, which causes paralysis. For those who don't know, it gives you about a 10% chance of acting when afflicted by it. Naturally, enemies have roughly a 75% chance of acting. Second is Scar Whip, which deals a respectable amount of physical damage and hits nine times. This isn't a problem if you have buffs and debuffs active, but if the boss gets it off without them active, Yuko will rarely suggest anything but healing, while Tomoe will probably end up suggesting a normal attack instead of something that debuffs. It, along with Zone Bind, shows up almost every turn after the boss' second phase starts, so good luck getting anything done before their charge attack goes off again and wipes your party.
That One Boss: The final boss of the main story can easily be this if you aren't prepared: Attacks twice per turn, one attack has 9 hits, loves to paralyze your party members, and after reaching half health it will unleash an attack that hits your entire party with every status ailment in the game. If you used/sold the only 2 Group Remedies or did not Knight Ran or Yuko (who both learn skills that negate status ailments as Knights), be prepared for a major struggle.
It's even worse in the rematch fight after obtaining the ending and unlocking the option to proceed into post-game after winning: All of the items used in the first fight are not returned to your inventory.
They Wasted a Perfectly Good Plot: Upon defeating Sako's shadow, you would think there would be some sort of resolution for Sako's feelings for Yuko (whether Yuko reciprocated them or not). Instead, afterwards its never really brought up again with Sako instead having feelings for the Instructor.
The Woobie: All of the girls to some extent upon learning about their pasts, but Ran takes the cake. What ruined her life wasn't her fault. Her sin was how she chose to cope with it. Kyouka is a close second, worked hard to enroll in a prestigious academy but ended up getting bullied by her wealthy classmates because of her plain clothes and family's middle-class income.
