アブノーマルクラスの生徒たちに、特別指令が下された。それは、クラス全員が２年生に上がるまでにランク４（ダレス）に昇級すること！さもなくば苦労して手に入れた「王の教室（ロイヤル・ワン）」から退去しなければならない。位階（ランク）アップのための次なる行事は「収穫祭」。短期間での実力アップのため、学校側は超強力な特別講師陣を用意した。新学期早々、入間たちの、まさに規格外な特訓の日々が始まる！

ロビンの親戚、バルバトス・バチコから特訓をつけられることになった入間＆リード。バチコはサリバンから直々に頼まれて、ロビンの助っ人として講師に着任した実力者だ。さぞハードな特訓の日々を送るはず……と思いきや、バチコから命じられるのは、使い走りや雑用ばかり。音を上げたリードは、ロビンのもとへ戻ることに。ひとり、悔しさに燃える入間。アスモデウスやクララが特訓に励んでいることを知り、ある行動に出る！

入間は、ようやくバチコに特訓をつけてもらえることになった。魔界きっての弓の名手バチコから出された条件は、自分だけの弓を作ること。魔具研究師団（バトラ）で見つけた、金剪（カナキリ）の長（オサ）の羽根に魔力を込め、弓を作る入間。しかし、出来上がった弓はバチコからことごとくダメ出しをされてしまう。大事なのは、「自分の欲しい弓」をイメージすることだとバチコは言うのだが…。

いよいよバビルス１年生最終バトル「収獲祭」が始まる。収穫祭は、約４日間にわたって行われるサバイバル方式の位階（ランク）昇級試験。制限時間内にジャングルに生息する魔獣や魔植物を狩り、その累計ポイントが最も高い者が優勝となる。ハードな特訓の日々に明け暮れたアブノーマルクラスの生徒たちは、特訓を行ったチームごとに対抗意識バチバチで、気合十分。いざ、危険な魔獣が潜むジャングルへ！

圧倒的武力で獲物を狩るアスモデウス＆サブノック組の前に、優勝者の有力候補「ドロドロ兄弟」イチロとニロが現れた。ドロドロ兄弟は２人に勝負を持ちかける。もし２人が勝てばすべてのポイントを差し出すと言うが……？同じ頃、多くの魔獣を従え優位に戦うケロリ＆カムイ組の一方で、ジャズ＆シュナイダー組は戦略的に他者からうばいポイントを稼いでいた。彼らの過ごした、フルフル軍曹による地獄のような特訓の日々とは……！？

Iruma and Lead are leisurely eating their ingredients while the other members of the Misfit Class are earning points. Iruma was experiencing a survivor's high after having his life put in danger. They decided to enjoy their time eating, putting a priority on surviving the longest in the Harvest Festival. They start talking about memories of a devi-mixer they went to and are just enjoying their time. However, they are suddenly approached by a mysterious kigurumi and...

「クララのおもちゃ箱」クララの魔術で着ぐるみの中に捕らえられた入間は、その中に広がる不思議なメルヘン空間へ閉じ込められてしまう！入間は心身ともに子どもになって、クララと一緒に思いっきり楽しく遊ぶ！「叫び声の響く夜」収穫祭１日目の夜。ジャングルでの過酷な環境に、リタイアする生徒が続出。そんな中、へとへとになったコナツ、ハルノ、アヅキ、ドサンコの４人がたどり着いた場所とは……！？

"Can We Make 100 Friends?": The owner of the amazing castle in the middle of the jungle was none other than Picero! Picero and Goemon were fighting in the Harvest Festival and had this castle to come back to. A busybody and a demon who marches to the beat of his own drum... This unlikely pair apparently have known each other for a while...

"The Students I'm Proud Of" Meanwhile, in the tutors' tent, there was a party going on. The tutors were all watching their students' performances during the Harvest Festival... and somewhere down the line, a rivalry was building up between the tutors.

The Dorodoro brothers provoke Asmodeus and Sabnock so much that they lose control and accept their challenge. However, their loss of control appears to be magical in nature...

Day 2 of the Harvest Festival, and the Iruma and Lead team were still at zero points, so they decide to try to get the Legendary Leaf to turn things around. With that in mind, they go visit Camui. Once they find him, they also encounter a horde of magical beasts and a little kingdom that had been established. The two are captured and suddenly brought in front of the queen of the kingdom, which just so happened to be Keroli?! Meanwhile, Ameri was thinking back about her time at the Harvest Festival, as she was watching Iruma's performance from the broadcast tent.

Ameri happens to run into Jazz and Schneider in the tent for all of the students who have forfeited. Apparently, they ran into a plot to get rid of all of the students of the Misfit Class from this competition. Around the same time, Iruma and Lead had begun looking for the Legend Leaf by using the lyrics to the Legend Leaf song as a clue. Iruma goes through the jungle, following what the lyrics said, and finds an entrance to an underground labyrinth. Deep within the labyrinth filled with traps and tricks, he encounters...

Iruma is trying to get back to the surface after exploring the underground labyrinth with Naphura. On their way up, he runs into his parents that shouldn't be in the netherworld. They're actually an illusion created by Orobas's magic. Iruma is overwhelmed by the illusion and falls off a cliff. Down below, Iruma continues to see nightmarish illusions. Will he be able to overcome his fears?!

The third day of the Harvest Festival. The announcement of how many points each has is announced through the jungle. Kalego mentions that a certain student still has zero points and tells them to shape up. After hearing this, Asmodeus and Clara immediately think of Iruma. Meanwhile, down in the underground labyrinth, Iruma figures out a way to get out...

Iruma is safely reunited with Lead. But apparently, Lead had the Vase of Endings he had successfully obtained stolen by Elizabetta. However, it appears as though the one who took the vase was not Elizabetta, but someone else. Lead uses his bloodline ability, Controller, that had been strengthened through Robin's training and tries to track Elizabetta down. What he ended up hearing were the voices of Elizabetta, Clara, and Keroli in a hot spring?!

The battle between Keroli's Magical Beast Kingdom and Picero and Goemon's squad continues. Elizabetta also joins the Magical Beast Kingdom and charms the enemy male students on the frontline. Meanwhile, Iruma and Lead also arrive at the Magical Beast Kingdom. After having Camui interpret what Naphula was saying, they find out that it was Orobas who had been attacking the members of the Misfit Class. Orobas seems determined to win, no matter what. Clara is now in danger, as she wandered off into the jungle by herself.

Asmodeus protects Iruma and Clara from Orobas, but he is disqualified from the competition because he directly attacked Orobas. As they watch Asmodeus walk off, they realize that Orobas has disappeared. Ocho had taken Orobas and fled. If Iruma and his friends don't retrieve the Vase of Endings, they can't make the Legendary Leaf bloom. But they have no idea where to even start. It is then when a certain someone appears before Iruma and his friends!

The Harvest Festival is coming to an end. Iruma and his friends have managed to obtain the Seed of Beginnings and the Vase of Endings. But they have no idea how to make the Legend Leaf bloom. Lead then remembers one of their old lessons with Suzie and remembers a certain spell... Iruma and Lead have exhausted their energy and mana at this point. Will they be able to successfully make the Legend Leaf bloom in the little time that they have?! Finally, the results are announced. Who will be the student who gets the title of Young King?

The Legend Leaf exploded in the sky and bloomed into beautiful flower petals. While everyone's in a celebrating mood, the award ceremony begins. Those who did excellently in the event, those who ended up forfeiting... How did all of the members of the Misfit Class do? Were they all able to reach the rank they needed to?! All of the mentors also are reunited with their students. How will the mentors respond to their students' performances during the Harvest Festival?

The night that the Harvest Festival ended, the instructors of Babyls got together at a pub to celebrate. Kalego usually never goes to these outings, but Balam catches him and forces him to go. Robin is getting ahead of himself as usual and the group even talks about Kalego's days as a newbie instructor. What is the most important thing about being an instructor at Babyls? We also get to see what happened to Ocho after he escaped into the jungle after the Harvest Festival.

Iruma goes over to Lead's house after getting a brand new gaming console. While they're playing games, Lead's older sister Shakky suddenly bursts into Lead's room, and she seems to be in a really bad mood...

Ameri and Iruma end up making homemade cookies together. But apparently, neither one of them has ever cooked something properly in their lives. They are an absolute mess in the kitchen and even Opera seems to have some trouble dealing with them...

Sullivan invited Bachiko to a huge breakfast to thank her for having contributed to the victory of her darling grandson, but also to inform her about a very worrying situation involving Iruma. After that, Iruma and Clara are invited to Asmondeus mansion where Iruma feels tremendous guilt for keeping his secret hidden from his friends. Back at school, the Misfits prepare for the Music Festival, their last chance to get all remaining Gimel's promoted to Dalet.