When you reach level 20, you can go do 3 quests with your lover in the three cities, of which you will receive 3 titles. Returning the quest rewards to Merlin in Ilya will net you the marriage token as well as a fourth title.
Recover 2% of HP and MP per 10 seconds.
Two kinds of weddings, the non-IM and the IM kind
Non-IM: Take the token to Angoya to get married. You will need 2500 lover coins, 2500 gold, and have been lovers for 100 days. You will receive the wedding ring, but you don't get a ceremony.
Wedding Ring: All stats +3, ATK/MATK: +10 (Note this is not an accessory, it goes in its own slot on the vanity memu).
IM: You get two more tokens from the item mall, and you can hold an actual ceremony on channel 5 in Red Coconut. You don't need to pay lover coins, gold or have to be lovered for 100 days. Your guests can join via the arena join mechanism. Note that admission is 30g for all guests.
IM Wedding Ring: All stats +10, ATK/MATK: +20.
IM Wedding Title: ATK/RATK/MATK/CRIT/MCRIT: +3%
If spouses interact more, they'll get better lover buffs. Note that the original lover buff is now 15%, and will be present regardless. This is an additional buff.
Max: ATK/DEF/MATK/MDEF/ACC: + 20, EVA: +5
Top: ATK/MATK/ACC: +15
Mid: DEF/MDEF/EVA: +2
Low: HP/MP: +1
*Spouse Damage Received: -25%, Spouse HP Recovery: +15% of HP/s, Duration: 5
*AOE +Malice Skill
*Teleports spouse to yourself.
*AOE Blind (-50% Hit), Duration: 15
Wedding party Instance (requires IM item).
An instance that drops certain IM items.
Again, IM or non-IM way.
non-IM way: Costs 2500g, requires both spouses to be near Merlin.
IM way: Costs nothing, can be unilateral.
Divorce Rewards (both ways): 10 15-minute 20% exp charms, 10-100g.