Formal:
* さようなら、愛しい人 (Sayōnara, itoshii hito): This is the most formal way to say goodbye love. It literally translates to "goodbye, beloved person."
* お元気で (Ogenki de): This is a polite and formal way to say goodbye, meaning "stay well." You can add "愛しい人 (itoshii hito)" after it to make it more romantic.
Informal:
* さよなら、愛してる (Sayōnara, aishiteru): This is a more informal way to say goodbye love, meaning "goodbye, I love you."
* バイバイ、愛してる (Bai bai, aishiteru): This is a very casual way to say goodbye love, meaning "bye bye, I love you."
* 大好き、またね (Daisuki, mata ne): This is a sweet and informal way to say goodbye love, meaning "I love you, see you later."
Other options:
* 愛してる、また会いましょう (Aishiteru, mata aimashou): This means "I love you, let's meet again."
* 永遠に愛してる (Eien ni aishiteru): This means "I love you forever."
The best way to say goodbye love in Japanese will depend on the situation and your relationship with the person.