---
title: "Koitsura Erosugi!"
description: "Main character Hiroki is a college student on vacations. His sister comes to live next room and visits protagonist with another neighbor girl. Hiroki is not rea"
image: "https://t.vndb.org/cv/43/125443.jpg"
---

# Koitsura Erosugi!

![Koitsura Erosugi!](https://t.vndb.org/cv/43/125443.jpg)

**Alternative Title:** こいつらエロすぎッ!

**Aliases:** They're Just Too Sexy!

**Developer:** Fiction7

**Release date:** Mar 29, 2008

**Platform:** Windows

**Language:** Japanese, English

**Rating:** 5.8/10 (41 votes)

## Description
Main character Hiroki is a college student on vacations. His sister comes to live next room and visits protagonist with another neighbor girl. Hiroki is not really interested in neighbors at first, but he plays a trick on the girls, and it triggers the start of new entertaining and exciting life.

[From [vndbreview](https://vndbreview.blogspot.com/2020/07/vn-of-month-march-2008-12riven-climinal.html)]

## Characters
### Hiroki (弘樹)
A pervert that likes young girls and big breasts. He lives together with his sister Makoto.

- **Gender:** Male
- **Hair:** Brown, Short
- **Eyes:** Hidden
- **Clothes:** T-shirt, Shorts
- **Subject of:** Blackmail
- **Role:** Full Brother, University Student

### Makoto (真琴)
The protagonist's younger sister, a first-year high school student attending a local school. She's on the swim team.

She constantly teases her brother with sarcastic remarks and often gets the better of him.
Being the impulsive type, she occasionally takes bold actions.

Her knowledge about sex is below average, and she's recently been troubled by a certain part of her body. Even so, she possesses deliciously large breasts.

[From [url=http://www.fiction7.com/erosugi.html]official site[/url]]

- **Gender:** Female
- **Hair:** Short, Orange
- **Eyes:** Amber
- **Body:** Kid, Olive, Tanline, Big Breasts
- **Clothes:** Shorts, Tank Top, Naked, Strap-on Dildo, Crop Top, Micro Mini Shorts
- **Personality:** Boku, Tomboy, Naive, Brother Complex, Mischievous
- **Role:** Full Sister, High School Student, Younger Sister, School Swimming Club Member, Pre-Story Virginity Loss to Protagonist
- **Engages in:** Lactation
- **Voiced by:** Kurumi

### Yuina (唯菜)
The girl who moved in next door. Through that connection, she became close with the protagonist and others.

Despite her appearance, she possesses keen intuition and insight, which often leads her to cause trouble. These incidents seem almost calculated, but the truth remains unclear.

Recently, her chest has finally begun to develop, and she seems very pleased about it. As the story progresses, she freely reveals her immature body.

[From [url=http://www.fiction7.com/erosugi.html]official site[/url]]

- **Gender:** Female
- **Hair:** Blond, Shoulder-length
- **Body:** Pale, Kid, Flat Chest
- **Eyes:** Amber
- **Clothes:** Dress, Naked, Panties
- **Personality:** Pervert, Mischievous, Insightful, Promiscuous
- **Engages in:** Blackmail
- **Role:** Neighbor
- **Voiced by:** Akatsuki Kotone

## Shops
- [Official Website](http://www.fiction7.com/erosugi.html)
- [DLsite](https://www.dlsite.com/maniax/work/=/product_id/RJ038608.html)

## Releases
### Japanese
- **2008-03-29**: Koitsura Erosugi! - Download Edition - [Official website](http://www.fiction7.com/erosugi.html), [ErogameScape](https://erogamescape.dyndns.org/~ap2/ero/toukei_kaiseki/game.php?game=10909), [DLsite](https://www.dlsite.com/maniax/work/=/product_id/RJ038608.html), [Digiket](https://www.digiket.com/work/show/_data/ID=ITM0019307/), [DL.Getchu](http://dl.getchu.com/i/item3328), [DMM](https://www.dmm.co.jp/dc/doujin/-/detail/=/cid=d_017222/fiction7-001)
- **2008-05-16**: Koitsura Erosugi! - Package Edition - [Official website](http://www.fiction7.com/erosugi.html)

### English
- **2025-07-22**: These girls are just too sexy!

## Tags
ADV, Lesbian Sex, Blood-related Brother/Sister Incest, Imouto-type Heroine, Male Protagonist, Linear Plot, Single Ending, Loli Heroine, Nukige, Protagonist's Blood-related Sister as a Heroine, High Sexual Content, Group Sex of One Male and Several Females, Hetare Protagonist, Small Breast Sizes Heroine (Non-Loli), Female Domination, Sexual Devices, Strap-on Dildos, Footjob, Boobjob, Heroine with Shorts, Blowjob, Lactation During Sex, Anilingus, Object Insertion, Protagonist with Phimosis, Pegging, Urethral Intercourse, Colored Name-tags, Meaningless Choices, Heroine with Tan Lines, Perverted Heroine, Straight Lolicon, Protagonist's Full Sister as a Heroine, Protagonist's Younger Sister as a Heroine, Mesugaki Heroine, Intercrural Sex, University Student Protagonist, Single Footjob, Feet Licking, Cunnilingus

## More Games from Fiction7
- [Itazura Satsuei](https://pinovel.net/v23598)
- [Koitsura Erosugi!](https://pinovel.net/v5567)
- [Kawaii Ko Mitsuketara Pero Pero](https://pinovel.net/v28252)
- [Uso no Idol Audition o Uke ni Kita Onna no Ko-tachi ni Doko made Yareru ka](https://pinovel.net/v18902)
- [Musume Seikatsu.](https://pinovel.net/v28218)
- [Netorare Hakusho](https://pinovel.net/v44191)

---
*View the full details at [pinovel.net/v5567](https://pinovel.net/v5567).*

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```