In the Online City Press L2 and a button (UP, DOWN, LEFT, RIGHT, X, CIRCLE, TRIANGLE, SQUARE) to get the character to "emote."

In the Online City Press R3 to bring up the text bar so you can send messages.

In the Online City Press L3 to bring up the Message History.

A quick tip on item collection: On some Gaiden Levels just defeat the required Character or Machine then return to the city (getting the defeat message) but you can still keep the items you grabbed.

This is very useful for Liu Bei & Sun Shang Xiang's "Birds", just kill Sun Shang Xiang and don't waste an hour killing the birds just quit and get her item drops.

      Officer Relationship Combinations
    * 1 // Cao's Influence - Cao Cao + Cao Pi + Cao Ren
    * 2 // Sun's Bonds - sun jian, sun ce, sun quan
    * 3 // Brother's Oath - Guan Yu + Liu Bei + Zhang Fei
    * 4 // Strategist's Reckoning - Sima Yi + Zhou Yu + Zhuge Liang
    * 5 // Turbans Sanctum - Zhang Jiao + Zhang Bao + Zhang Liang
    * 6 // Burning Love - cao pi, zhen ji
    * 7 // Young Love - Zhou You + Xiao Qiao
    * 8 // Virtuous Love - Yue Ying + Zhuge Liang
    * 9 // Devoted Love - Lu Bu, diao chan
    * 10 // Pure Love - Liu Bei + Sun Shang Xiang
    * 11 // Xiahou's Spirit - Xiahou Dun + Xiahou Yuan
    * 12 // Faithful Devotion - sun quan, zhou tai
    * 13 // Warrior's Generation - Guan Yu + Guan Ping
    * 14 // Princesses Dance - dong zhuo, diao chan
    * 15 // Nemesis Bond - Cao Cao + Yuan Shao
    * 16 // Iron Men - Dian Wei + Xu Zhu

      Type Combinations using 4 Cards
    * 17 // Imperial Majesty - 4 "Lord" Cards
    * 18 // Poison Strategy+ - 4 "Wood" Cards
    * 19 // Engulf Strategy+ - 4 "Fire" Cards
    * 20 // Heavy Strategy+ - 4 "Earth" Cards
    * 21 // Stun Strategy+ - 4 "Metal" Cards
    * 22 // Freeze Strategy+ - 4 "Water" Cards
    * 23 // Seal Strategy+ - 4 "Dark" Cards
    * 24 // Disband Strategy+ - 4 "Light" Cards
    * 25 // Ingenious Minds - 4 "Strategists" Cards
    * 26 // Legendary Courage - 4 "Officer" Cards
    * 27 // Wei Phoenix - 4 "Wei" Cards
    * 28 // Wu Tiger - 4 "Wu" Cards
    * 29 // Shu Dragon - 4 "Shu" Cards
    * 30 // Chief's Oath - 4 "Other" Cards

      Type Combinations Using 2 Cards
    * 31 // Imperial Presence - 2 "Lord" Cards
    * 32 // Poison Strategy - 2 "Wood" Cards
    * 33 // Engulf Strategy - 2 "Fire" Cards
    * 34 // Heavy Strategy - 2 "Earth" Cards
    * 35 // Stun Strategy - 2 "Metal" Cards
    * 36 // Freeze Strategy - 2 "Water" Cards
    * 37 // Seal Strategy - 2 "Dark" Cards
    * 38 // Disband Strategy - 2 "Light" Cards
    * 39 // Agile Minds - 2 "Strategists" Cards
    * 40 // Fearless Courage - 2 "Officer" Cards
    * 41 // Wei's Ambition - 2 "Wei" Cards
    * 42 // Sun's Solidarity - 2 "Wu" Cards
    * 43 // Shu's Aspiration - 2 "Shu" Cards
    * 44 // Chief's Union - 2 "Other Forces" Cards

Perform the actions below to unlock additional costumes:

    * Fourth Costume - Beat 50 Quests with a character
    * Third Costume - Reach Level 10 with a character

The following characters can be unlocked by performing the actions below.

    * Diao Chan - Beat Battle of Hu Lao Gate (5-Star Version)
    * Dong Zhuo - Beat Battle of Luo Yang and Battle of Mei Castle (5-Star Versions)
    * Lu Bu - Beat Chapter 6 of Story Mode
    * Meng Huo - Beat Unification of Nan Zhong (Beat Nanman Quests from the Second Gatekeeper in Chapter 3)
    * Yuan Shao - Beat Zenith Tower Request Mission
    * Zhang Jiao - Beat Yellow Turban Rebellion (5-Star Version)