Rito decided to go for a check up at Mikado's office and when he got there she wasn't there but luckily Oshizu was.

"Hiya Oshizu!" Greeted Rito happily.
"*Yawn* Hi there Rito." Greeted Oshizu back while being a little tired.
"If you don't mind, could you do a little check up?" Suggested Rito.
"Sure thing." Said Oshizu.

Rito then sat on a bench and Oshizu started the check up. And when Oshizu was ready she also decided to vaccinate him just in case since winter has already come there, but she didn't realize that she had given a wrong medecine for Rito.
After that Rito left and Mikado was walking in the hallway to go to her office.

"Oshizu, where is the medecine spike i had on my table?" Asked Mikado with a comcerned tone.
"*Yawn* I gave it to Rito." Explained Oshizu.
"You what?!" Said Mikado.
"W-Was that bad?" Asked Oshizu now concerned too.
"It was meant for Lala and you gave it to Rito?" Explained Mikado.
"O-Oh no! I messed up!" Shouted Oshizu sadly.
"Hmm well it will last for a week so it's not that dangerous but you should be more careful. Ok?" Explained Mikado.
"Y-Yes!" Said Oshizu.

Rito was walking on the hallway when he felt strange.

"Guh! W-What's going on?" Said Rito to himself.
"Rito-kun!" Shouted Run happily.
"Wait up Run! Guh, what's going on?" Said Rito again.
"What's wrong?" Asked Run concerned.
"I-I don't know. I didn't feel like this when i visited Mikado's office and while Oshizu checked my eye sight and my ears." Explained Rito while being in pain.
"I-I'll go tell Mikado!" Explained Run and rushed to Mikado's office.

Rito then started to feel more bad when it suddenly stopped.

"Huh? It just stopped. Well i'll go to class." Said Rito and continued his way to class.

When Rito reached his class other students looked at him as he walked to his desk.

"Uh, Rito. Is that... you?" Asked Barry.
"What do you mean? Of course i am." Explained Rito with a confused look.
"Well uuuh, how should i put this... you have something behind you." Explained Barry.
Huh? Something behind me?" Said Rito confused and then looked behind him and saw that he had a Devilukean tail with the blade looking attachment.
"YAAAAH! H-HOW DID THIS HAPPEN?!" Asked Rito while being confused.
"Rito what happened?!" Asked Lala, Yui, Momo and Sairenji.
"Uh Rito seemed to get your alien tail Lala, Momo." Explained Saito who was sitting on his desk.
"WHAT?! HOW?!" Asked the girls.
"Oshizu accidenly gave Rito a medecine that was meant for Lala" Explained Run.
"Huh? T-Tell me there's a cure too Run." Demanded Rito.
"No need to panic, it will only last for a week." Explained Run.
"Oh, well i guess it's not that bad i guess." Said Rito with a much calmer voice.

Momo then walked up to Rito and grabbed his tail and rubbed it.

"Uh, what are you doing Momo? If you're trying something, it's not working." Explained Rito.
"Oh uh r-right." Said Momo a bit embarrased.
"What was she trying Rito?" Asked Barry curiously.
"She probably tried to get me feel, uh well aroused since for some strange reason she, Lala and Nana feel that way when their tails are touched." Explained Rito with an embarrasing tone.
"*Sigh*" Barry only sigh's at that statement.
"Y-Yuuki-kun try lifting that Honekawa's desk." Suggested Sairenji.
"Huh, why?" Asked Rito with a confused look.
"Well since you have a Devilukean tail, then maybe you also have the powers that Devilukeans have." Explained Sairenji.
"Huh, that actually makes sence. Sure i'll try." Said Rito and walked to Honekawa's desk and lifted it up.
"Y-Yep, Rito has the power." Said Kirito.
"Whoa cool!" Said Barry excited.

Before the class starts Oshizu apologizes to Rito what she did but he's not mad at her since she didn't mean any harm and was also probably unaware of it.
When the school ended Rito walked to home with everyone else and when they got home, Mikan was shocked by the news that Rito had aquired a Devilukean tail but soon calms down when she hears that it won't be permanent. After that they start to eat.