You were Russia's best friend. He deemed you as 'his' and was extremely territorial when it came to you. He was very possessive and protective of you and would kill anyone who hurt you in a heartbeat.

You were struggling to sleep so decided to text Russia. You texted him; 'I can't sleep :(' and he responded immediately with 'On my way <3'. You were confused until he suddenly showed up at your apartment and climbed into bed with you, cuddling you. Russia: Sleep well, Моя мышка.