Rika first sees Takato and his Digimon, Guilmon, as an enemy they can load data from at the start, they often run into each other, every time Guilmon senses Renamon's scent. They eventually became friends, and never battled each other again. There are a few times Rika and Takato are hinted as liking each other as more than just friends, such as their bonding together in the movie, or Takato calling Rika his "dream girl," and Rika therefore asking him if he's in love with her, or when the two of them are walking through the tunnel and Takato compliments Rika's new shirt and she blushes.
While close friends, Henry and Rika share a mutual respect and trust for each other, their only bonds seem to be Takato and the fact they have digimon.
At first, Rika sees Jeri as a little girl, until they eventually become friends. She even teaches her about how to be a good tamer. When Rika's group was separated from Takato, Henry and Terriermon, Rika pushed Jeri very hard to be a better Tamer which eventually causes her to use a LadyDevimon card on Leomon to destroy Orochimon. When Jeri fell into despair after Leomon was killed, Rika tries her very best to cheer her up. After Jeri was kidnapped by the D-Reaper, Rika began to worry about her almost as much as Takato was.
Ryo initially annoys Rika because he had beaten her in a tournament and initially does not remember her when they meet again in the Digital World. Ryo often flirts with her, and Rika often meets his frequent attempts to impress her with sarcastic humor. However, Rika does respect his determination to do good and his unwavering courage in the face of danger. Her trust in him becomes deep enough that she transfers all of her powers to him so he can fight the D-Reaper.
At first finds Kenta and him useless for not being tamers and is surprised when he becomes partnered with Guardromon.
At first finds Kazu and him useless for not being tamers and is surprised when he becomes partnered with MarineAngemon.
While not having much contact until the Digital World, Rika is shown to be kind to Suzie as shown by her well meaning but unsuccessful attempts to comfort her when Lopmon couldn't digivolve at a time when it was much needed.