Seiken Tsukai no Proposition


Seiken Tsukai no Proposition
TitleSeiken Tsukai no Proposition
Original title聖鍵遣いの命題
AliasesSeiken Tsukai no Meidai, 聖鍵遣いのプロポジション, Proposition to the Holy Key Contractant, Sekapoji, 圣键遣的命题
LengthMedium (10 - 30 hours)
Publishers UnicoЯn
Same setting
Dolphin Blade


This is the debut work for UnicoЯn.

There exists a legend about a king who obtained a relic from a lost civilization and used its power to grant any wish to unite the world. This relic, ‘Sora no Ison’ (Legacy of the Sky), was sealed afterwards by the ‘holy keys’ somewhere in the world. Countless persons have attempted to find it, but none of them could even find a trace of its location.

Haruto is a hopeless guy who was forced by the headmaster Spiano to attend the Academy, but ended up skipping all classes. When she made him work part-time, an unfortunate incident caused him to carry a huge debt to her. To pay off the debt, he was unwillingly tasked to explore to the depths of a sealed ruins as part of a supplementary test. His fellow test-taker Akina mentioned that it was rumoured that the elusive relic was sealed deep in the ruins. Vowing to become rich and to show Spiano up, he faced the challenge with heightened vigor.

[From Hau~ Omochikaeri!]


Hart Grancer
Hart Grancerハルト・グランセル 
MeasurementsHeight: 176cm
Birthday1 January
Hair, Black, Short, Spiky Bangs, Straight, V Bangs
Eyes, Amber, Tsurime
Body, Average Height, Pale, Slim, Teen
Clothes, Blazer, Cufflink, Decorative Belt, Loafers, Necktie, Pendant Necklace, Robe, School Uniform, Shirt, Shrug, Trousers
Items, Greatsword, Handgun, Sword
Personality, Arrogant, Brave, Charismatic, Chuunibyou, Funny, Insightful, Kind, Lazy, Modern Tsundere, Narcissist, Otaku, Overconfident, Pragmatic, Proactive, Relaxed, Smart, Womanizer
Role, Boyfriend, Friend, Rival
Engages in, Kigurumi, Martial Arts, Swordsmanship, Teasing
Subject of, Debt, Teasing
Engages in (Sexual), Bathroom Sex, Butterfly, Cowgirl, Outdoor Sex, Quickie Fix, Reverse Cowgirl, Seventh Posture, Sex in Public Places, Sex in Water, Sixty-nine, Spoons, Standing Sex, Tominagi, Virgin Sex
Subject of (Sexual), Blowjob, Boobjob


Regardless of who his opponent is, Hart always insists on looking down on them. Despite acting like a big shot, hei is completely reliant on his guardian, Spiano. In other words, he is a useless person. He often tries to become independent but isn't able to hold a job for long because of his high pride. Thanks to that, his debt keeps raising and raising. He has the ability to discern lies.

Main characters

Akina Akitsuki
Akina Akitsukiアキナ・アキツキ 
MeasurementsHeight: 156cm, Bust-Waist-Hips: 89-58-85cm
Birthday12 October
Hair, Orange, V Bangs, Waist Length+
Eyes, Violet
Body, Average Height, E+ Cup, Pale, Slim, Teen
Clothes, Cardigan, Knee-high Socks, Loafers, Necklace, School Uniform, Thigh-high Stockings
Items, Sword, Twin Blade Sword
Personality, Hardworker, Kind, Loud, Modern Tsundere, Short-tempered, Watashi
Role, High School Student
Engages in, Swordsmanship
Subject of, Inferiority Complex, Teasing
Engages in (Sexual), Virgin Sex
Subject of (Sexual), Cowgirl, Missionary, Seventh Posture
Voiced byHazakura Yukine


A bright and cheerful girl that loves cute things. Akina a hardworker but because everyone around her is gifted, she carries feelings of inferiority. Quite normal and average in everything outside of her boob size. When agitated, she swings her fists around while yelling "idiooooot".

Alesha Hammond
Alesha Hammondアリーシヤ・ハモンド 
MeasurementsHeight: 151cm, Bust-Waist-Hips: 88-57-79cm
Birthday3 March
Hair, Pink, Short
Eyes, Amber
Body, Average Height, Pale, Slim, Teen
Items, Bag, Book, Greatsword
Personality, Kind, Shy
Engages in, Swordsmanship
Engages in (Sexual), Blowjob, Virgin Sex
Subject of (Sexual), Doggy Style, Missionary, Quickie Fix
Voiced byKotorii Yuuka


The kind of silent girl that would read a book in a corner.

Isn't good with crowds or talking to people.

Though it's hidden by her uniform, has a surprisingly nice body.

Elise von Richthofen
Elise von Richthofenエリーゼ・フォン・リヒトホーフエン 
MeasurementsHeight: 156cm, Bust-Waist-Hips: 86-56-88cm
Birthday15 August
Hair, Blond, Intake, Long, Ringlet
Eyes, Blue
Body, Average Height, Pale, Slim, Teen
Clothes, Beret, Coat, Flower, Knee-high Socks, Miniskirt, Necklace, Pleated Skirt, School Uniform
Items, Handgun
Personality, Arrogant, Closet Pervert, Friendly, Naive, Serious, Talkative, Watashi
Role, High School Student, Noble, Ojousama
Engages in (Sexual), Blowjob, Virgin Sex
Subject of (Sexual), Missionary, Quickie Fix, Seventh Posture
Voiced byMisaki Momoko


The third daughter of a noble who is quite prideful. Despite her haughty attitude she is easily pushed around. Elise gets easily carried away when she gets flattered. Likes flashy and sparkly things. Even when not asked about them, Elise loves to go on about her "family's glorious teachings".

Lang Linghua
Lang Linghua狼 鈴華 
MeasurementsHeight: 141cm, Bust-Waist-Hips: 72-50-70cm
Birthday4 February
Hair, Ahoge, Orange, Spiky Bangs, Waist Length+
Eyes, Blue
Body, Fang, Kemonomimi, Kid, Pale, Short, Slim
Clothes, Ankle Socks, Hairpin, Jacket, Miniskirt, Scarf, School Uniform, Sports Shoes, T-shirt
Items, Bag, Fanny Pack
Personality, Clumsy, Confident, Energetic, Friendly, Loud, Third Person, Tomboy
Role, High School Student
Engages in, Martial Arts
Engages in (Sexual), Blowjob, Virgin Sex
Subject of (Sexual), Doggy Style, Missionary
Voiced byHayase Yayoi


A very nimble and active girl who is always overflowing with energy. Despite her young looks and childish personality, Linghua loves to act like an older sister in the presence of the others. She is also weak to headpats.

Saki Aihara
Saki Aiharaサキ・アイハラ 
MeasurementsHeight: 158cm, Bust-Waist-Hips: 86-60-85cm
Birthday18 January
Hair, Blue, Sidehair, Straight, V Bangs, Waist Length+
Eyes, Black
Body, Average Height, Pale, Slim, Teen
Clothes, Jacket, Knee-high Boots, Miniskirt, School Uniform, Turtleneck Shirt
Items, Handgun
Personality, Classic Tsundere, Stubborn, Watashi
Role, High School Student, Writer
Engages in (Sexual), Boobjob, Virgin Sex
Subject of (Sexual), Missionary, Quickie Fix, Sexual Blindfold
Voiced byKusuhara Yui


A very serious girl. She has a fine figure which is admired by the girls around her. Unknown to everyone, Saki writes light novels (mostly romance) during her free time.

Selene Grancer
Selene Grancerセレーネ・グランセル 
MeasurementsHeight: 144cm, Bust-Waist-Hips: 78-52-78cm
Birthday3 May
Hair, Blond, Curly, Sidehair, V Bangs, Waist Length+
Eyes, Green, Tareme
Body, AA Cup, Pale, Short, Slim, Teen
Clothes, Dress, Leggings, Necklace, Ribbon Hair Accessory, School Uniform
Items, Handgun, Ninjato
Personality, Mysterious, Nature Lover, Outgoing, Stoic, Sweets Lover, Taciturn, Watashi
Role, High School Student
Engages in, Martial Arts
Engages in (Sexual), Blowjob, Sixty-nine, Virgin Sex
Subject of (Sexual), Doggy Style, Quickie Fix
Voiced byFujisaki Usa


While Selene always sports a blank expression and is hard to read on the outside, at her core she is a very passionate person, but at the same time a bit spoiled. She has a small body that animals like and because of this, Selene is in charge of feeding Spiano's adopted pets. Though short, she has a very fit body.

Side characters

MeasurementsHeight: 139cm, Bust-Waist-Hips: 72-50-73cm
Birthday24 December
Julia Lewty
Julia Lewtyユリア・ルーティ 
MeasurementsHeight: 153cm, Bust-Waist-Hips: 80-55-85cm
Birthday20 July
Voiced bySasamoto Kazune
Laura Asteria
Laura Asteriaローラ・アステリア 
MeasurementsHeight: 158cm, Bust-Waist-Hips: 82-56-86cm
Birthday20 April
Personality, Energetic, Outgoing, Pretending, Uchi
Role, Antagonist
Engages in, Teasing
Engages in (Sexual), Virgin Sex
Subject of (Sexual), Doggy Style, Sitting Sex
Voiced bySawasawa Sawa
Lynette Lea
Lynette Leaリネット・リーア 
MeasurementsHeight: 153cm, Bust-Waist-Hips: 87-60-87cm
Birthday29 June
Hair, Hair Loopies, Red, Sidehair, Twin Tails, Waist Length+
Eyes, Green
Body, Pale, Slim
Subject of (Sexual), Doggy Style
Voiced byUeda Akane
Migliarino Milt
Migliarino Miltミリアリーノ・ミルト 
MeasurementsHeight: 151cm, Bust-Waist-Hips: 79-55-80cm
Birthday17 September
Hair, Twin Tails, Violet
Eyes, Violet
Personality, Classic Tsundere
Role, Waitstaff
Engages in, Cleaning, Cooking
Engages in (Sexual), Virgin Sex
Subject of (Sexual), Doggy Style
Voiced byYuuki Honoka
Spiano Grancer
Spiano Grancerスピアーノ・グランセル 
MeasurementsHeight: 150cm, Bust-Waist-Hips: 84-57-82cm
Birthday3 November
Hair, Curly, Green, Sidehair, Waist Length+
Eyes, Pink
Body, Average Height, Pale, Slim, Teen
Clothes, Necktie, Pantyhose
Items, Wheelchair
Personality, Serious, Sloppy, Sweets Lover
Engages in, Drinking
Engages in (Sexual), Drunk Sex, Virgin Sex
Voiced byArihara Hotaru


Despite her young age, Spiano is the principal of the academy and an elite of the administrative bureau. Though she may seem like a very serious person considering her status, Spiano is actually very sloppy and lazy when alone or at home, though she is quite competent when at work. Has eyes for nothing but sweets and shouchuu. Spiano is forced to use a wheelchair because of a certain incident, though she isn't too inconvenienced by it.