No, this isn't an April Fools joke. You've already seen what we do for those >_>
No what we have here is an actual in progress English patch of Rockman EXE 4.5, which is one of the few titles in the Battle Network series that has not been released outside of Japan. Spikeman has been working on translating this game for the last couple of years and released a partial patch for the ROM of the game a while ago. The result translates some parts of the game into english, however a majority of it is still in Japanese.
Is the game playable however? Personally I don't have a problem with it, even though I don't understand a single bit of Japanese (hasn't stopped me from nearly beating Ryusei no Rockman 3 however). Some key parts are in English like Battle Chip names and the main Menu tabs, though there are some who will absolutely refuse to play a game that isn't fully translated.
It pretty much comes down to a judgment call on if you want to play it or not. For those interested in how the game works, I've made a basic tutorial video on Youtube. The patch can be found here, however you'll have to find the ROM of 4.5 on your own for obvious reasons.