| This article contains spoilers from the manga that has not been shown in the anime. Please continue reading at your own risks.|
During the progress leading toward Miku's confession, the sisters – who all escape from their respective courses – were revealed to be helping Miku from behind the scene.
- Ichika, Nino, Yotsuba, and Itsuki are revealed to help Miku in one way or another during Chapter 84.
- Yotsuba's reasoning to help Miku is because she is the timid one and want everyone to be happy.
- Ichika did meet with Fuutarou back in Elementary School Kyoto Trip. She played a card game with him during the night at the Inn.
- One Young Nakano (other than Ichika) met with Fuutarou first, this is when they buy the charm (shown in Chapter 34).
- Nino and Ichika both fake being sick to join Couse E. Itsuki and Yotsuba are also in Course E due to unknown reasons. This is another proof of how the sisters often have the same train of thought.[page 2]
- Ichika, Nino, Yotsuba, and Itsuki are revealed to cause the peculiar events surrounding Miku during Chapter 84. In order of events:
- Ichika collided with Miku so she doesn't run away.[page 1]
- Ichika and Nino simultaneously promoted costume play from "House of Costumes" to prevent Miku from leaving [page 2].
- Nino distracted Maeda and Takeda by leading them away from "House of Costumes" to the haunted house. [page 6]
- Meanwhile, Ichika disguised as Miku and talk with the "House of Costumes" clerk which resulted in the clerk pushing Miku to wear the dress.[page 6]
- Nino, through hugging Fuutarou, accidentally caused Miku to fall into the lake.[page 8]
- Itsuki, for some reason, brought a spare set of underwear that Miku can use (Chapter 79).
- Ichika set a no-entry sign near Miku and Fuutarou's area, so they can have some private time together.[page 10]
- Yotsuba picked up Miku's bread (Chapter 80), however she forgot it at the hotel.[page 10]
- Nevertheless, Ichika brought Miku's bread with her and stealthily put it beside Miku (Chapter 84).[page 11]
- Callback to Chapter 1:
- Yotsuba implies that initially, the black-hair Fuutarou was not Nino's type.[page 4]
- Nino knows that Ichika took interest in Fuutarou during their first encounter, presumably the one at the school when Ichika initiate the conversation.[page 4]. However, Ichika stated that "it wasn't until that night..."
- Ichika getting silent during that night in Chapter 25 is because she recognized Fuutarou as the boy she met years ago.[page 14-15] Her reaction is never explicitly shown. 
- Ichika admitted that their meeting at the inn during the Elementary School Kyoto Trip is one of the factor that made Ichika like Fuutarou.[page 14-16].
- Yotsuba's reasoning to help Miku is because she is the timid one and wants everyone to be happy.[page 12]
- Ichika commented that their infighting is unnecessary.[page 12]
List of characters in order of their appearance:
- Miku Nakano
- Fuutarou Uesugi
- Ichika Nakano
- Nino Nakano
- Yotsuba Nakano
- Itsuki Nakano
- Young Nakano
- "I... just want everyone to be happy." - Yotsuba Nakano[page 12]
- "Five years ago... Even if it was... Just for a short time... I'm sure it was because we shared that moment... That I came to love you." - Ichika Nakano[page 16]
- "Although Fuutarou-kun most likely isn't going to believe me anymore, but at the very least... That memory alone wasn't a lie." - Ichika Nakano[page 17]
- "Trying to get a leg up on each other and getting in each other's way...this fighting has all been completely meaningless. We're not enemies." - Ichika Nakano[page 20]
- Yotsuba wears an outfit with diamond-shaped design, reflecting her order of birth.
- The card game in page 4 does not have Heart number 6 and Heart number 8, a possible nod to Chapter 68 and romance.
- This is the second time Nino hugs Fuutarou from behind, the first was when he picked her up with a motorbike in Chapter 59.
- Ichika's somber reaction during Chapter 35 toward Fuutarou's question might also be a hint towards the revelation about her meeting 5 years ago with him.