Yesterday's enemies could be today's friends.

Yesterday's enemies could be today's friends., with variations such as yesterday's enemy is today's friend, is a phrase in linguistical culture and surprise catch phrase by Moe in Densetsu no Starfy 3, as 『今日のテキはあすの今友』. The gist is that no one should segregate people as 'good' and 'bad', because deep down we are human; and we all have something in common, and that furthermore a so-called 'enemy' could become one's friend.

Moe said the phrase in relation to Ogura; who had passed away, in resentment to Starly who insensitively called him a 'bad guy'; since he was the main villain of Densetsu no Starfy and Densetsu no Starfy 2. It is known as a deep moment in the The Legendary Starfy series. In Japan, this is also related to 闇 任天堂 (Yami Nintendo), dark or more mature moments in Nintendo video games.