Fam vs. Friend

Family vs. Friends is an upcoming Splatfest event in Splatoon 2. It will be held for all regions from 2019-01-04 to 2019-01-06. It was announced on 2018-11-30 on social networks before the release of version 4.3.0. The results will be given on 2019-01-06.

Details
The Splatfest will take place over the course of 48 hours instead of the normal 24 hours. It will be the second 48-hour Splatfest in Splatoon 2.

In addition to the normal changes at Splatfest time (central stage appearing in Inkopolis Square, all stages shown at night time), there will be several changes unique to this Splatfest as part of the Chirstmas / New Year's Eve theme, similar to the changes for Splatoween: https://youtu.be/Apk3tmMt3-c
 * The in-game logo will show "Frosty Fest" instead of "Splatoon 2".
 * Inkopolis Square will have additional white and gold decorations in the shapes of icicles, snowflakes and stars.
 * The various stages will have have decorative stickers, graffiti, and other unique decorations.
 * Existing graffiti will be modified, mainly by depicting characters as decorated with ribbons, bows, and snowflakes.
 * The sky appears to be overcast and outdoor areas such as the square will see snow falling.
 * Players' ink appears especially shiny, with glittering particles inside.
 * A special news article in the Nintendo Switch news will reward players with 4 unique pieces of headgear, in the holiday spirit:
 * New Year's Glasses DX
 * Twisty Headband
 * Festive Party Cone
 * Eel-Cake Hat
 * and will have different colour schemes (with Pearl's outfit being mainly gold and Marina's being mainly white).
 * Various in-game characters such as and  as well as jellyfish in the Square will wear party hats.

Trivia

 * This Splatfest was first shown in a commercial for the Nintendo Switch that was uploaded by Nintendo online before the event's official announcement on Twitter later that day.
 * The inkling script on the Splatfest Tees shown in the commercial read "TRICK" and "TREAT" instead of "FAMILY" and "FRIENDS," respectively.