Primary

• Rikka's Grandmother Grandmother of Rikka Takanashi
• Rikka's Grandmother Wife of Rikka's Grandfather

Extended

• Rikka Takanashi Classmate of Yuuta Togashi
• Rikka Takanashi Classmate of Shinka Nibutani
• Rikka Takanashi Classmate of Makoto Isshiki
• Rikka Takanashi Younger Sister of Touka Takanashi
• Rikka Takanashi Girlfriend of Yuuta Togashi