There are many anime of this type. Here are some examples: 1 Kirito and Asuna in Sword Art Online (A Certain Love) 2. Lelouch (Lelouch Langley) in "The Rebel Lelouch" and Nunnally (Nunnally Langley) on behalf of CCG 3. Eren and Skali in The Attacking Giant 4. Misaki Katsuki (Kagamine Rin) and Kaesaka (Kagamine River) in The Evil Crown 5. Ikari Touma and Saten in Tokyo Ghoul These are just a few examples. The plot of this type of anime is full of ups and downs and is very popular with the audience.