I've Been Killing Slimes for 300 Years and Maxed Out My Level (2021)

S1E4 We Went to a Dragon's Wedding

Leila, Laika's older sister, is about to tie the knot, prompting Azusa and her friends to head to Mount Rokko, where the Red Dragons reside. The mountain is alive with activity as the Red Dragons gather to celebrate the wedding. Azusa extends her congratulations to Leila, and the ceremony proceeds smoothly... until the Blue Dragons, who harbor a deep-seated rivalry with the Red Dragons, launch a surprise attack!