AkuMa Series

The AkuMa series is a series of songs created by uniMemo-P in collaboration with Bucchigiri-P and illustrated by Kitano Tomotoshi. The series is composed by 3 song with the last one explaining the background behind the previous songs.

Background
The sort of plot behind this messy series talks how Rin receives the help of a demon girl called MaRin to finally confess her love to Len. MaRin lends her part of her power to the original Rin transforming in a demon girl too, then both Aku MaRins assault Len in an attempt to conquer his heart with disastrous, yet hilarious results.

The series is quite random, full with jokes, parodies and fan-service in major or minor degree. Despite the randomness of the series one thing can be assured: Len ALWAYS going end dressed in a embarrassing way and humiliated at the end of each song.

Pretty Panties ☆ Aku MaRin (プリティパンティ☆悪マリン)

 * Nicovideo Broadcast
 * Youtube Broadcast
 * Sung by Kagamine Rin, backup by Kagamine Len and Hatsune Miku
 * Composed by uniMemo-P in collaboration with Bucchigiri-P
 * Illustrated by Kitano Tomotoshi

The song starts with both demon girls entering abruptly to Len's Room in the Christmas Night to play some pranks on him. Len panicked ask what happened to Santa Claus and who are they. Answering the question, both girls present themselves as "Pretty Panties ☆ Aku MaRin", they wish him a "Merry Christmas and Happy Birthday" and proceed to give him their "Christmas gift". Saying the magic words "Rinrenraririn" they assault him, take his clothes off and dress him with their gift: The majokko school swimsuit from Len no Bousou.

Both girls mocks of the confused and angered Len saying that suit fits him very well and that finally is dressed as his "true self". As both Demon Girl failed in their "real mission", they give their good-bye to Len and leaves the room through the same windows which they entered. Len humiliated were going to protest when Miku enters to his room, complaining about the noise, just to find him dressed in that awkward attire.

Pretty Fundoshi ☆ Aku MaLen (プリティふんどし☆悪マレン)

 * Nicovideo Broadcast
 * Youtube Broadcast
 * Sung by Kagamine Len, Megurine Luka and Kagamine Rin, backup by Kaito and Kamui Gakupo
 * Composed by uniMemo-P in collaboration with Bucchigiri-P
 * Illustrated by Kitano Tomotoshi

By unknown means Len appears as a demon too and along Tako Luka decide play the same prank that he suffered on the previous song, this with Kaito as victim. They enter to his room breaking through the tatami, panicked by the abrupt intrusion Kaito ask who are they, answering the question the Demon Boy introduces himself as "Pretty Fundoshi ☆ Aku MaLen". Then inviting to everybody to check the show (with exception of the MaRins) Len says the magic words "Rinrenraririn" and began to take Kaito's clothes off for dress him with the same majokko swimsuit with he was ridiculed by the MaRins in the previous song.

In that moment Len discovers the things aren't resulting as he expected, when he and Tako Luka tries to remove Kaito's fundoshi they discover that the guy actually is using two overlapping fundoshis (Kaito inmediately states that he feels insecure with just one), and then when they finally dresses to Kaito with the majokko suit they discover that actually is enjoy it. Despite that Len mocks and compares him with a perverted idol, is in that moment when the MaRins burst in.

One of the MaRin angered for seeing what Len did with her gift confronts Len while he tries to justify himself, meanwhile the other MaRin finds Kaito's fundoshi in the floor. In that moment the first MaRin decides to punish Len obligating to use the fundoshi (with the help of Kaito and Tako Luka). Len complains that this time he should been playing the prank while both MaRins mocks and then obligates him to sing Len no Bousou along Kaito. Seeing that isn't enough moe the first MaRin suggest step on them for make them sing in a higher pitch. Listening the commotion Gakupo enters katana in hand just to end as another victim of both MaRins.

Pretty Panties ☆ Aku MaRin Ep. 0 (プリティパンティ☆悪マリン ep.0)

 * Nicovideo Broadcast
 * Youtube Broadcast

Explaining the background behind the two previous songs, the events of this song actually occurs before, during and after the events of Pretty Panties ☆ Aku MaRin and Pretty Fundoshi ☆ Aku MaLen songs. The song starts showing a timid Kagamine Rin in her room, practicing her confession to Len in front a mirror. Incapable to overcome her shyness she makes a wish to the mirror asking more courage for express her feelings to Len. To her surprise the mirror answers, her reflection was replaced by a girl identical to her with an punkish and devilish attire, surprised Rin ask where and who is she, the girl chuckles and indicates that she is inside of the mirror for then introduces herself as "Pretty Panties ☆ Aku MaRin". After get out of the mirror the Demon Girl begins to organize with Rin. After Rin ask her strength the Demon Girl says the "magic word" Rinrenraririn to transform her in a Demon too... well, actually (and like in the previous songs) she just takes Rin's nightie clothes off. Embarrassed Rin begins to cry, while AkuMarin says that she should stop the tamtrum and that kind of frilly dresses aren't going to work to conquer Len's heart. After receive her Demon Lolita attire Rin is transformed in an Aku MaRin too, ready to go in rampage.

Meanwhile Len in his room says that is the Christmas Night and despite he doesn't believe in Santa Claus isn't worry because he believes that Miku is the one who fills his sock, then he turns to his windows just to see Gakupo Santa Claus. The girls in Rin's room see him too, and considering him a hinder in their plans they blast him away and then assault Len in his room, triggering the events in "Pretty Panties ☆ Aku MaRin" song.

After the failure of the first song the girls regroup in Rin's room and with a freakier idea, MaRin suggest to Rin use her tongue for win Len's heart (ironically it worked in the end). After practice a bit they begin her second assault triggering the events of Pretty Fundoshi ☆ Aku MaLen song.

After another failure Rin insist in confess her feelings. Aku MaRin suggest her practice her confession with her, Rin manages to spit out her confession causing that Aku MaRin kiss her triggering a fusion of both girls. Meanwhile, outside Rin's room, Len is with Gakupo. The boy is preparing to assault Rin's room decided to put end to this. Gakupo ask if enough "armor" as Len is barely dressed with a fundoshi, Len says that he shouldn't worry. He enters to the bedroom just to discover that he committed a deadly mistake: Both girls are now fused in a powerful and voluptuous Demon Queen. Unable to control her tongue the fused MaRin swallows Len in one gulp. Then parodying El Shaddai: Ascension of the Metatron's gameover/continue sequence, the time is reversed to the moment when Len is preparing to enter to Rin's room. Len ask to Gakupo his best armor which result to be a Princess dress and enters to the room for the final battle.

Parodying a button mashing sequence, Len and the fused MaRins engages a "tongue battle". In middle of the combat Len ask what's wrong with them and why they are after him. Rin replies shyly that she wanted to tell him something and finally spits out her confession, causing that their tongues tangle up and forcing up a kiss between them. Len confused wakes just to find himself in a comprising situation. Meanwhile he tries to understand what's going on Meiko, Kaito and Miku enters to the room. While Meiko and Kaito congrats to Len for his "achievement" Miku panicked screams "Noooo! the world isn't ready for this". The video finally ends with zoom out of the house and the scream of the humiliated Len.

Trivia

 * The name of the Demon Girl actually is a wordplay. This one can be translated as "Evil Marin" (悪マリン Aku MaRin), where Marin is in fact a girl's name. Also this name is homophone of 悪魔リン (Akuma Rin) which can be translates as "Devil Rin". The name of Len's Demon version imitates this (悪マレン Aku MaLen or Aku MaRen), but fails ironically as Maren and Malen are actually girl's names, if this was accidental or intentional is currently unknown.
 * The magic word Rinrenraririn that the Imps say before undress for change the clothes of their victims actually is the name of the first work of uniMemo-P.
 * About the song "Pretty Fundoshi ☆ Aku MaLen":
 * When Len and Tako Luka are undressing to Kaito, he calls to Len the Great Magistrate. This is actually a joke of the old japanese culture when magistrates harassed the girls in kimono.
 * About the song "Pretty Panties ☆ Aku MaRin Ep. 0":
 * The moment when Len is preparing to burst into Rin's room, his dialog with Gakupo and his eventual demise in hands of the fused Aku Marin actually is a parody of the El Shaddai: Ascension of the Metatron's E3 2010 Trailer
 * When the talk between Gakupo and Len repeats after the time reversal Len appears dressed as Lady Gaga.
 * The Len's Princess Dress actually is the Rin's nightdress in the beginning of the video.
 * It's hard to notice it but after the kiss scene, when Len wakes up you can notice that Rin is practically naked, barely covered by her briefs (making even more embarrassing the situation for the poor Len).