Adding to the points Ezodagrom stated, we have ARKS bingo event. The JP Wind and Rain 2015 had a bingo card, but 2014 version didn't. So my bet goes to the 2015 version.
Here's a brief summary of "Gone with the Wind and the Rain 3" (the actual name of the JP 2015 version) page from the JP PSO2 Wiki.
Area: Naverius - Forest, 1 area
Objective: accumulate quest points. Similar to our Wopal UQ (The Dead Sea Where Dragons Gather)
Difficulty: JP had XH difficulty, but this doesn't necessarily mean we will have XH on NA.
- Falspawn bosses: Zeshraider, Dark Ragne, Wolguarda
- Falspawns: those from Ruins area or earlier areas
- Sylvant bosses: Rockbear, Fang Banshee, Fang Banser, De Marmoth, Snow Banshee, Snow Banser
- Sylvants: mainly from Forests area
- Oceanid bosses: Leomaduraad, Nept Casadohra
- Others: Frog Rappy, Mesetan, Tagamikazuchi, Nyau, Mr. Umbra, Mr. Bwomf
- Rare enemies of some of the enemies above.
The V2 series weapons shown on the site news announcement, didn't drop on the JP version. Likely to be NA special.