The English subtitle for Volume 4 is "Notes on Camp."
Fuutarou and the Nakano Quintuplets go on a school camping trip, which has a notorious legend involving the bonfire dance in the last day. Fuutarou, who has to prepare the Test of Courage, doesn't take the legend seriously; on the other hand, the Nakano sisters believe the legend and try to become Fuutarou’s dance partner.
The volume cover features Miku Nakano in her student uniform, with light-blue colored flower petals scattered in the background.
- Loves western music, but has zero ability to pick up spoken English.
- Favorite animal: hippopotamus
- Her beloved long hair is constantly getting caught in train doors.
- Favorite animal: rabbit
- Currently keeping a Sengoku Period game she borrowed from Yotsuba for her own.
- Favorite animal: hedgehog
- Her one worry is that her name takes more strokes to write than her sisters'.
- Favorite animal: camel
- Will eat stew with white rice.
- Favorite animal: kangaroo
- Lets his little sister cut his hair with normal scissors every time.
- Favorite animal: gorilla
- Favorite animal: penguin
- Chapter 24: The Binding Legend: First Day
- Chapter 25: The Binding Legend: Day 2 ①
- Chapter 26: The Binding Legend: Day 2 ②
- Chapter 27: The Binding Legend: Day 2 ③
- Chapter 28: The Binding Legend: Day 2 ④
- Chapter 29: The Binding Legend: Day 3 ①
- Chapter 30: The Binding Legend: Day 3 ②
- Chapter 31: The Binding Legend: Day 3 ③
- Chapter 32: The Binding Legend: Day 2000
- Two of Ichika's male friend are fantasizing about her, and they don't mind a sleazy Ichika.
- Maeda is seen paired together with a girl (later become his future wife) for the Test of Courage. He is angry at Fuutarou for being missing.
- Two of Nino's friend comment that boys are idiots, only to make a blushing remark about a particular guy soon after.
- The History Teacher and PE Teacher shake hands together during the bonfire event.
- In the first chapter of Volume 4, there is Nakano Quintuplets' finger game which involves all five fingers. In the last chapter of Volume 4, Chapter 32, each of the Nakano Quintuplets holds one of Fuutarou's finger.
- The flower petals' color in the volume cover background represent the sisters' color scheme: Light blue for Miku and Miku's headphones & sweater