Namco X Capcom is a crossover strategic, action hybrid roleplaying game. It takes some original characters, and characters from many other game series. (ex. Xenosaga [KOS-MOS <3], Tekken, Street Fighter, the Tales series, Megaman, and many other old time series.)
The story is about two characters, the original ones, named Reiji and Xiaomu who work for a organization named Shinra and deal with the paranormal.
The gameplay is pretty nice, with your basic tactics map movement but when you take an action against an enemy, you go to a Valkyrie Profile-esque (Though less options) battle system and can commence combos, and even co-op attacks.
This game, sadly, was never ported to the western globe. However, a full translation of the game has been made, and is playable.
The translation was done by the fangroup Transgen. There is also a sequel-ish named Mugen no Frontier: Super Robot Wars OG Saga.
Ahh, I remember this game~ I couldn't understand the story but I liked the gameplay~
Let's see, in Xenosaga there are KOS-MOS, Shion and MOMO (They are counted as one unit), various Gnosis enemies~
In Tekken: Jin, Heihachi (Enemy, then ally), Devil Jin (HARD enemy), and King and Felicia.
In the Tales series, they only took character from Tales of Destiny series, so there's Stahn and Rutee, and Leon/Judas, and various enemies (Green Ropper is one of the most annoying enemies in the game. They can poison you~)
In Megaman, they only used characters from Megaman Legends series, so you have Megaman and Roll, Tron and Kobun, Juno (enemy), and various reaverbots~
There are LOTS of characters here (Ryu, Ken, Karin and Sakura, Klonoa and Gantz, Bravoman and Wonder Momo, Morrigan & Lilith, Rose, etc....), but unfortunately, you only get to pick 10 of your favorite characters for the final battle (which lasted 2 hours for me). Oh, and you can't go back to previous maps to level up. There are a total of 50 stages in this game, each lasting at least 1 hour each (except the introductory battles).
For those who wants to play this, here's a tip for you. Don't think you've almost won a map when there's one enemy left. Enemies WILL ALWAYS have reinforcements (So annoying really)~