Jouichirou is very much Jotaro biased. He has had a great admiration for the man since he was a little kid and did/does everything to get his attention, much to Josuke's disappointment. Jouichirou's bond with Josuke is a bit wonky because of this.
Not only was Jotaro partly the reason Jouichirou obtained a stand, he also awakened his love for marine life.
Touma and Gogo
Touma and Seiua are twins with two very different personalities. Gogo would often tell Jotaro that she sees herself in the boy. She and Touma are mild-tempered, preferring to be quiet and listen with a smile over animatedly talking, yet with those they feel comfortable they come out of their shell.
Seiua and Bini
People see Seiua as intimidating or even scary, but he's actually a big soft goofball, just like his dad. Being the youngest twin makes him insecure, especially when Touma gets regularly praised for his skills and accomplishments.
In these situations, Seiua seeks comfort in his mom. He and Bini are both extremely sensitive and understand each other exceptionally well on an emotional base.
Seiua and Jolyne
Seiua's mischievous side comes up when he tries to prank Josuke or Jouichirou. Especially when Jouichirou comes into the picture, Seiua and Jolyne like to team up. Jolyne's dislike for Jouichirou helped them get closer.
Kazumasa and Kakyoin
Although Kakyoin's experience with kids wasn't all that great, the redhead does have a weak spot for Kazumasa. After the twins developed their stand, everyone was too busy with them to notice that Kazumasa could see the apparitions as well. Bringing Stands out around the kids would normally go unnoticed before this, but after the boy interacted with Hierophant Green, Kakyoin would secretly let him play with his stand.
Minami and Josuke
Minami is Josuke's only daughter and seen as his little baby bun. The day she was born Josuke knew his family was complete. Minami would cling to her dad constantly. He's also the only one who's able to calm her down when she's upset.
Minami and Tomoko
Minami adores her grandmother. Although Tomoko has 5 grandchildren she all loves equally, having a granddaughter feels special to Tomoko. The two of them spend time together often.