Content Note / Age Disclaimer All romantic, intimate, and sexual content in this story involves only consenting adults aged 18 and older attending Toka Academy, a prestigious university-preparatory institution. Riko is a non-sexual child character (approximately 11 years old) who appears only in wholesome, familial contexts as Miyu’s little sister. She has no involvement in any romantic or sexual scenes. This is a work of adult fiction intended for readers 18+.
© MallZombie, 2026. All Rights Reserved.
THE UNDERGROUND TUTOR
by MallZombie
VOLUME ONE
Table of Contents
- Prologue
- Chapter 1: The Request
- Chapter 1.5: The Day the Madonna Noticed the Background Guy
- Chapter 2: The Lunchtime Rumors
- Chapter 3: A Jewel in the Rough
- Chapter 4: A Request from the President?!
Timeline
- Prologue (Late Spring, one year ago): Kenji helps young Riko in the rain near Toka Academy.
- Main Story (Current Year, Late Spring / Early Summer): The events of Chapters 1–4 occur over several weeks.
Cast of Characters (All romantic/intimate characters are 18+)
- Kenji Tanaka: Second-year student and the reluctant “Underground Tutor.”
- Yumi Sato: First-year idol / Madonna — bubbly and popular.
- Aoi Fujimoto: Third-year archery captain — sharp and intense.
- Hana Ishikawa: Shy, bookish girl seeking confidence.
- Miyu Takahashi: Student Council President — elegant and perfectionistic.
- Riko Takahashi: Miyu’s ~11-year-old little sister (wholesome, non-sexual only).
Thank you so much for reading. Please subscribe for more chapters. I plan on releasing three chapters per week on Monday, Wednesday, and Friday. Volume Two will begin on Monday, April 13. This is my first time writing. I value your feedback, so please leave a review and lots of comments. I promise to read every one and will reply to as many as I can keep up with! I hope you enjoy these characters as much as I do! Thanks again!! — MZ
THE UNDERGROUND TUTOR
by MallZombie
VOLUME ONE
Prologue
Late spring, Toka Academy district, Tokyo. Rain battered the streets like it had a personal grudge against the city. Kenji Tanaka, a student at Toka Academy who still hadn’t figured out how to look like he belonged anywhere, trudged home from cram school with his umbrella tilted against the wind. In spite of his umbrella, his blazer was already soaked at the shoulders, and his leather shoes squelched with every step.
That was when he spotted her. A small girl stood alone under the awning of a closed stationery shop, soaked to the bone. Her dark hair was cut in a simple bob that stuck to her cheeks in wet clumps. She wore the standard navy blue school sailor uniform, now plastered to her skinny frame.
She wasn’t crying, but her shoulders were hunched and her arms clutched tightly around a soggy pink backpack as if she was worried it might float away if she were to let go of it.
Kenji slowed, then stopped a polite distance away. “Hey… you okay?”
The girl looked up. Big blue eyes, wide with worry, met his. “I… I got separated from my sister after my piano lesson. The rain started and I tried to run home, but I turned the wrong way and now I don’t know where I am…”
Her voice wobbled on the last word.
Kenji crouched a little so he wasn’t towering over her. “What’s your name?”
“I’m not supposed to tell strangers,” she grumbled.
“Oh. Well, that makes perfect sense. Hmmmm… Uh, my name is Tanaka. Kenji Tanaka. Sooo…. Now we’re not strangers. I guess. Do you know your address or your onee-san’s phone number?”
She shook her head and shivered. “We just moved into our new house. I know the street name but not the number… and my phone is dead.”
Kenji’s cheeks ballooned as he blew out a puff of air, not because he was annoyed — just contemplative. He held out his umbrella so it covered her too.
“Come on. There’s a convenience store two blocks that way. You can dry out there, and I’ll let you borrow my phone charger so you can recharge. Sound good?”
The girl hesitated, then gave a tiny nod and stepped under the umbrella. Her small feet left little wet prints beside his larger ones as they trudged along.
At the konbini, Kenji explained the situation to the clerk. While the girl jabbered to her sister in a relieved torrent over her now-resurrected phone, Kenji bought her a warm can of milk tea and a hot meat bun. When she hung up, her cheeks were still flushed but the panic was gone.
“Onee-chan’s coming. She says thank you.”
“No big deal,” Kenji said, rubbing the back of his head. “Just try not to wander off in the rain again, okay? Wouldn’t want you to get eaten by a scary clown hiding in a storm drain.”
The girl burst out laughing, showing Kenji an absolutely radiant smile he never would have expected to see on the face of the dismal little waif.
She clutched the warm can like a treasure and looked up at him with huge blue eyes. “You’re really kind, Onii-san.”
Kenji laughed awkwardly. “Nah, I’m just a normal guy. Anyway, now you’ll be fine.”
“Yeah, Onee-chan says she’ll be here in five minutes.”
“Excellent. Then, objective complete!” Kenji gave the most charming smile he could muster. “I’m afraid I have to get home now. Take care, Ojochan.”
On his way out the door Kenji gave a quick wave back, said thanks to the clerk, and jogged off into the rain before anyone could make a fuss.
His good deed done for the day, Kenji sped home and honestly never gave the incident another thought.
Meanwhile Miyu Takahashi, carrying a large umbrella and wearing her school’s red wine-colored blazer, rushed into the store. “What happened, Riko-chan? You scared me half to death.”
Riko’s voice was quiet but certain. “I got lost in the rain. But a boy helped me. He had an umbrella and bought me milk tea and waited with me. His name was… Kenji.”
Miyu raised an elegant eyebrow. “Kenji?” She draped a raincoat over her sister’s shoulders.
“Uh-huh. He must go to your school, Onee-chan. His blazer was the same color as yours.” Riko hugged her knees, a small, dreamy smile spreading across her face. “He was really nice. I think when I grow up, I’m going to marry him.”
Miyu let out a soft laugh, half-exasperated, half-amused. “You’re still a child, Riko-chan. You can’t just decide to marry someone because he gave you milk tea.”
“I can too,” Riko said stubbornly, pressing the warm can to her cheek. “I’m going to remember him forever. Tanaka Kenji. He’s the kindest Onii-san in the whole world.”
Miyu just shook her head with an exhausted little smile. “Come on. Let’s go, you little disaster.”
