Yeah, but it depends on where on the series you are.
Fourze’s first appearance, as a cameo, nonetheless, is actually a funny scene that happens almost at the end of the previous rider’s movie, where he helps OOO (Oozu) fight a monster. It’s canon, happening just after Fourze’s re-entry on Earth’s atmosphere in the series Episode 10 (after the “Armstrong Kick”) =>
(Sorry the subs are in Thai, but you’ll get the gist of what’s going on, just skip to 0:53:30 to see it, it includes the handshake but you can see Gentaro did not have his trademark haircut at the time… odd)
Now Fourze+OOO+W/Double Megawar Movie comes next, it’s just before episode 15, the fight against Perseus, watch it all, till the end of credits, there’s a special cameo right at the very end!
Next, Kamen Rider X Super Sentai Super Hero Taisen is right between Episodes 24 and 25, just before “Graduation Day” happens - though Fourze appears like 10% of movie, he gets a major appearance at the end, and there’s even some amazing stuff happening around with the Gokaiger, so its worthy the watch:
The Astro Switch Secret Report + Hyper Battle DVD you can watch after Episode 32, before Episode 33 (after Aries), the first is a funny recap, the second is an interactive DVD movie, with special guest Kamen Rider Amazon, so you watch them in this order:
First, Astro Switch Report: http://www.youtube.com/watch?v=vuoooFtkuR0&list=PLFKrAGs_82doHYI6VW_xhyN6pvzTtKCkJ&index=52
Second, Hyper Battle DVD: http://www.youtube.com/watch?v=2P-a_35i5q4&list=PLFKrAGs_82doHYI6VW_xhyN6pvzTtKCkJ&index=53
Finally, the “Everyone, Space is Here”, the actual Fourze movie, you must watch it after Episode 44, just before 45 (after the reveal of Gemini, just before Pisces - it’s the only way it makes sense, though you’ll get to see Pisces before it appearing in the show) it’s big and it’s great, special guest Mikie Hara (google her; you’re welcome), and at 00:23:30, Wizard’s first cameo, though he also appears on the Show’s finale…
The movie: http://www.youtube.com/watch?v=nw6KdDg2zFs&list=PLFKrAGs_82doHYI6VW_xhyN6pvzTtKCkJ&index=51
I just don’t have the Wizard’s Megawar movie yet, it shows the Kamen Rider Club, five years later, sorry.