Press ESC to close

A naughty little sister? Marshmallow Imouto Succubus on Steam this September!

On September 9th, Sekai Project and Denpasoft announced the release of ORCSOFT‘s Marshmallow☆Imouto☆Succubus☆. This VN also has its own OVA animation from Luna Pictures, airing in 2016 with 2 episodes.

The game is releasing on Steam this September 22nd and will be available in both English and Simplified Chinese.


Tsukikawa Keisuke had a strange dream. That dream involved his younger sister but instead of her usual, innocent self, she had lust in her eyes. So he finds out that a succubus lurks within her! How will he choose between his innocent sister and the allure of a lustful succubus?!


Marshmallow☆Imouto☆Succubus☆ is a nukige VN from developer DWARFSOFT and publisher ORCSOFT. Its Download Edition and Package Edition released on July 24th 2015.

DWARFSOFT is a nukige-focused imprinted brand by ORCSOFT. It began activity on June 20th 2015 with this game as their first release. Some of their games are available in English, such as Zero Chastity: A Sultry Summer Holiday (FAKKU!), My Life as a Cult Leader (Kagura Games), The Voluptuous DEMON QUEEN and our Shoebox Apartment Life (Shiravune), and Iku Iku Succubus (FAKKU!)
Their most recent release is Muchimuchi♥Dekapai♥Marakui♥Succubus Mama wa Hatashite Mama na no ka? and there are news of more to come.


Tsukikawa Keisuke had a strange dream. That dream involved his innocent younger sister, Saki. Saki was a naïve girl who even believed that babies were made from just kissing. However in his dream, Saki’s innocence was replaced by eyes filled with lust as she creeps into Keisuke’s bed. The next day, Saki was her same innocent self to Keisuke’s relief. He was relieved that it was a merely a dream.

However, he soon learns from his father that a succubus lurks within his little sister. Having to choose between his dear, innocent little sister and the allure of a lustful succubus, what will Keisuke do?



  • Visual novel with 2 possible endings
  • Japanese voice acting (Except protagonist)
  • Voiced line playback
  • History/backlog function


Tsukikawa Saki
VA: Katakura Hina

She is the sister-in-law of the main character, Keisuke. However, her true identity is a succubus. While her succubus personality is on the surface, she is unconscious. She believes that she and Keisuke are blood siblings.

She is a first-year student at Hoshikou private school.
She is a healthy, kind, and hardworking person, but she is terribly naive.

Saki, such as she is, honestly loves her older brother, Keisuke – in other words, you – who always puts her sister first. However, she does not understand the difference between familial love and sexual love, so she wonders why her sister cannot marry her brother. However, now that her succubus nature is about to be awakened, Saki is unconsciously beginning to see Keisuke as a man.

The second personality of Saki, who is usually asleep — the true nature of a succubus.
Unlike the gentle Saki, this Saki is aggressive, devilish, sexually open, and lecherous at heart.
Unlike Saki, who does not know her true nature, this side has inherited all the memories of what Saki’s personality has experienced.

She is very aware of how attractive her own body is, and she will not hesitate to use it to seduce Keisuke, even to the point of sex.
Succubus are known for sleeping with any man to replenish their magical power and relieve their desire, but Saki only has sex with Keisuke.

Is it because she knows how Saki, her first personality, feels?

Manabe Riri
CV: Misonoo Mei

She is a classmate of Keisuke and sits next to him. In addition, she is part of the same folklore study club as Keisuke.

While on the outside she is a perfect beauty, on the inside she behaves like an old man who is not afraid to spout off a series of bold, vulgar jokes. Because of this, Keisuke tends to treat Riri like a friend of the same sex.

Riri’s true identity is actually a succubus like Saki. A certain incident leads her to reveal her true identity to you.

She is sexually uninhibited but a beginner in love.

The succubus version of Manabe Riri.

Tsukikawa Morihiro

The hero — your father.
He is an eccentric folklorist who believes in the existence of demons, vampires, and werewolves. He is ridiculed as a “monster hunter” at academic conferences.
He often goes abroad for fieldwork and tends to be away from home.
He writes books on European mythology and folklore. He earns a surprisingly modest income from his manuscripts and royalties.



previous arrow
next arrow

The game is releasing on Steam this September 22nd, so wishlist it now!

If you enjoy our work, please follow us on Twitter for more visual novel content and join the community in our forums and discord server: we’re pretty active there!

In addition, you can also support us on Patreon or by buying us a Ko-fi.


KEVINNGW808, Indonesian PVZ Gamer and Youtuber. Always succ at PVZ, including PVZ Mods. Likes animes, VNs, and Hololive. Enjoys video editing, computering, chinese song, memes, and cats too.

Notify of

Inline Feedbacks
View all comments