Onee-san wa Joshi Shougakusei ni Kyoumi ga arimasu by Ryota Yuzuki — Ongoing

Volume 1
Chapter 1: The one whom Onee-san loves released May 21 '18
Chapter 2: The Allure of the Meow-Meow released Sep 9 '18 Toys
Chapter 3: The plan to escort the little girl to the amusement park! released Sep 9 '18
Chapter 4: Miss Minori-chan and the camera released Nov 24 '18
Chapter 5: A teacher, a little girl and a swimsuit released Feb 19 '19 Swimsuits
Chapter 6: Minori-chan vs Hime-chan released Apr 7 '19
Chapter 7: A Small Start released Jul 11 '19
Chapter 8: Girls talk and antics released Oct 14 '19
Chapter 8.5 released Jun 10 '20
Volume 2
Chapter 9: Minori-chan and the Day of Self-Control released Nov 8 '19
Chapter 10: Coco’s Birthday released Nov 13 '19
Chapter 11: Our first double date released Nov 20 '19
Chapter 12: That's the disease of love! released Dec 18 '19
Chapter 13: A Training Day with the Big Sis she admires released Jan 12 '20
Chapter 14: The Ones Who Love Onee-san released Mar 18 '20
Volume 3
Chapter 14.5 released May 19 '20
Chapter 15: The current little girl and the last little girl released May 8 '20
Chapter 16: Adult and Kid released Jun 8 '21
Chapter 17: Minori-Chan Sensei and The Cultural Festival released Jun 8 '20
Chapter 18: Everyone's Own Love released Jun 18 '20
Chapter 19: Strategy For Defeating The Onee-Loli Blues released Jun 24 '20
Chapter 19.1 released Jul 3 '20
Chapter 19.2 released Jul 3 '20
Chapter 19.3 released Jul 3 '20
Chapter 19.4 released Jul 3 '20
Chapter 19.5 released Jul 3 '20
Chapter 19.6 released Jul 3 '20
Volume 4
Chapter 20: I Want To Lead This Love released Jul 7 '20
Chapter 21: Little Girl Love Simulation released Jul 10 '20
Chapter 22: Girlfriends' First Night released Jul 19 '20
Chapter 23: Holy Night PinPoint Game released Jul 24 '20
Chapter 23.5: Finding The Moles released Aug 4 '20
Chapter 24: Taking Care of A Feverish Girlfriend released Aug 19 '20
Chapter 25: The Pink(y) Lips Promise of Koko and Minori released Aug 28 '20
Chapter 25.5 released Aug 28 '20
Volume 5
Chapter 26: Panic at the Christmas Party released Oct 2 '20
Chapter 27: Enthusiastic Studying released Oct 12 '20
Chapter 27.5: Twitter April Fool's Extra released Oct 12 '20
Chapter 28: Night Fever of Wordly Desires released Nov 10 '20
Chapter 29: Small and Big Bomb released Nov 21 '20
Chapter 30: Challenging Minori's Delusions released Dec 4 '20
Chapter 31: Secret Valentine released Dec 15 '20
Chapter 31.1: Loitering Smoke Area released Dec 25 '20
Chapter 31.2: Another Eve released Dec 25 '20
Chapter 31.3: Extra 3 released Dec 25 '20
Volume 6
Chapter 32: A New First Year released Jan 8 '21 Science babies
Chapter 33: How to Make Babies released Jan 20 '21 Science babies
Chapter 34: My First Feeling released Jan 27 '21
Chapter 35: Once Again, I'll Make You Notice Me released Feb 9 '21
Chapter 36.1: The Start of the 2 released Feb 14 '21
Chapter 36.2: The Start of the 2. The other 2 released Feb 14 '21
Chapter 36.3: Manga Life is Quite Ecchi released Feb 14 '21
Chapter 36.4 released Feb 14 '21
Chapter 36: The Great Seduction Plan released Feb 9 '21
Volume 7
Chapter 37: How to Not Scratch an Itch released Jul 18 '21
Chapter 38: Magical Girl Kokopure released Jul 26 '21
Chapter 39: The Onee-san I Look-Up To released Jul 26 '21
Chapter 40: Wants and Needs released Aug 9 '21
Chapter 41: Lesson for Coming of Age released Aug 9 '21
Chapter 41.1: What Happened After Chapter 37 released Oct 10 '21
Chapter 41.2: What Happened After Chapter 41 released Oct 10 '21
Chapter 41.3 released Oct 10 '21
Chapter 41.4 released Oct 10 '21