Katsubou Method ~The addictive Formula~ - Story, Characters and Other info

I've been set to listening to Katsubou Method recently. When I searched for some info I found nothing to give me some leads so here's my translation of the characters' profile and main points to understand the story. Here's the official site where I got the info in case you want to visit ^^

Disclaimer: I DON'T own anything. The pictures, characters and story belong completely to otomate records.

VERSIÓN AL ESPAÑOL AQUÍ

❁Story❁

Trapped in eternal darkness, in time.

One day a girl suddenly dissappears. 

All traces of her existence gone, as if she never existed to anyone. 

Her sudden disappearance altered her entire world completely. 

The girl that opened her eyes among deep darkness

 heard the familiar voice of her childhood friends

We're not human.

We can't share the same timeline as you. 

That's why we'll give you "an immortal body", same as ours. 

❁Characters❁
Vol. 1

The King with no name, leader of the immortal 

[CV. Satoshi Hino]

The immortal King 

The first character the girl meets when she awakes in the mansion. 

Bitten by the king the girl still needs to turn into an immortal creature. 

In time, lust hidden deep inside as well as confessions... 

will take over--

Drinking blood,

longing for everlasting pleasure. 

Vol. 2

The younger twin brother, your childhood friend. 

[CV. Okamoto Nobuhiko]

Natsuki

High-school second year. 17 years old.

His parents are both human. An incident in his past 

made him inheriting the power of the king,  therefore became half-inmortal.

He's the heroin's classmate and childhood friend. 

Since kids they were raised as siblings. 

He's more outgoing than his older brother, with a slightly twisted personality.

I'm sorry, let me eat you 

just a bit... a little bit.

Vol. 3

The older twin brother, your childhood friend.

[CV. Okizu Katsuyuki]

Haruki

High-school second year. 17 years old.

The same as his younger brother, Natsuki, he's half-immortal.

Opposite to his brother he's concerned about the great thirst that the magic power gives him, however he keeps it a secret.

On one side, his human emotions weakened while on the other side his desire to monopolize strengthened.

I've been longing for you to become

a half-made monster, just like me. 

Vol. 4

The King of demons

[Tachibana Shinnosuke]

Shitorii

The right hand of the King of the immortal.

When he approaches the girl in a human disguise he calls himself "Kannou Souji".

His true identity is the King of demons.

He's vowed to the King absolute loyalty as well as blind faith.

Feel.

The fear in the name pleasure. 

Vol. 5

The only family

[CV. Kaji Yuuki]

Nase Ichiya

Third year college student. 21 years old.

Heroin's stepbrother. 

The heroin met him when he was in high-school, his mother had a second marriage.

He gets lost in the mansion when he goes all by himself

to look for his missing stepsister.

I... only I

am never going to abandon you--

Vol. 6

The awakening of the immortal blood

[CV. Kakihara Tetsuya]

Someya Izumi

Third year college student. 22 years old.

School friend of Ichiya.

He's not acquainted with the heroin but

he does know that Ichiya has a younger sister.

After the girl's disappearance

Ichiya also goes missing 

He gets lost in the mansion

aiming to find them both.

I've got the feeling something is changing

there's a breaking sound 

❁Other info❁

►Immortal

An existence with an immortal body.

They feed with the blood of "humans or immortal people".

►Immortal people

They're humans that've been bitten by the King, usually they can't stand the magic power in the blood and die, however, in extraordinary cases some humans do adapt.

Such humans acquire an immortal body and become immortal people. 

More than the lack of emotions, body heat and memories, personality suffers great transformation.

►Half -immortal

With the sole purpose of creating a pure immortal existance, the leader created a peculiar existence, that of Natsuki and Haruki.

When a pregnant woman was bitten by the King, the fetuses absorbed the magic power.

Those aforementioned fetuses were Natsuki and Haruki.

Being incomplete the tranference of the magic power straight to the mother, her death accelerated, dying when the twins were little. 

►Demon

A different existance to that of the King of the immortal. 

Even though Shitorii is also a the King of demons, he worships the King of the immortal and remains by his side. 

►The promised day

The day Natsuki and Haruki decided to abduct their childhood friend. 

►Parents' second marriage

The girl is thirteen and Nase Ichiya seventeen when their parents have a second marriage and become siblings.

Until the day Ichiya's mother protects the girl during an accident the four of them lived together as family. Nowadays their father lives abroad, Ichiya’s also left home and the girl lives by herself.

►The awakening

The immortal blood of a distant ancestor returns and awakens in Someya Izumi.

His parents as well as his grandparents and younger brother are common humans.

So this is it. I hope this was helpful ^^