Tail Concerto
Tail Concerto was the first game developed by CyberConnect, before the developer reformed as CyberConnect2. It was released in 1998 for the PlayStation.
There are several references to Tail Concerto in the .hack series, including character name cameos and in-fiction advertisements.
Games Tetralogy
Characters
| Original | Cameo | ||
|---|---|---|---|
| Waffle Ryebread |  |
 |
Waffle |
| Panta |  |
 |
Panta |
| Alicia Pris |  |
 |
Alicia |
| Stare Pris |  |
 |
Stare |
| Flare Pris |  |
 |
Flare |
| Princess Teria |  |
 |
Teria |
| Cyan Garland |  |
 |
Cyan |
| Fool |  |
 |
Fool |
Terajima Ryoko also appears to be based on Princess Teria, both visually and in terms of personality. They have similar names, and wear fancy clothing befitting their financial status. BlackRose shares some features with Alicia, as both have darker skin/fur tones compared to most other characters, both have forward personalities and can be brash. Additionally, BlackRose's player's name also starts with an A; Akira.
This similarity between these characters is further expounded upon in Volume 4, which features a bonus dungeon event with romantic undertones. Kite apparently doesn't pick up on the subtext and makes the faux-pas of inviting both BlackRose and Terajima Ryoko to the same dungeon. The girls are both shocked to find themselves in the party together.This prompts the girls to argue in a way that mirrors the arguments Alicia and Princess Teria had over Waffle.
Advertisements
In the Games Tetralogy, the Desktop News Application features advertisements for games by CyberConnect. The first Tail Concerto advertisement features the three Pris Sisters. From left to right; Flare, Stare, and Alicia. The second advertisement features King Hound III and Waffle. The second advertisement also adds a "2" to the Tail Concerto logo, which implies there was a direct sequel in the .hack universe. In reality, no Tail Concerto 2 game was released. A direct sequel, Tail Capriccio, was hinted at by the the developers, but never materialized. As there were never any official announcements, nor cancellations, it is now widely considered vaporware.
Items
In the Japanese release, Mia's starting weapon is called Black Cat's Blade, another reference to the Black Cats Gang from Tail Concerto.
Summon Skill
In the Games Tetralogy there are 5 pieces of "Cats Equipment" that can be acquired through trading; Cats Blades, Cats Hat, Cats Mail, Cats Gloves, and Cats Boots. If the player equips every piece of the Cats Equipment, a secret summon skill becomes available; it is called Meooow. The description reads, "Summon Black Cat Gang!" The skill summons a kitten, who commands three Drill Mecha to attack the target. The kitten is a standard mob encountered in Tail Concerto, and are the generic members of the Black Cats Gang. The Drill Mecha are from one of Tail Concerto's boss battles, where they are piloted by kittens.
| Tail Concerto | Meeeow! |
|---|---|
 |
  |
 |
 |
Music
bonus0: 800 Significant Seasons Bonus Track: Panta-Kun
bonus2: 800 Significant Seasons Bonus Track: Cyan and Princess Teria
bonus3 800 Significant Seasons Bonus Track: Tail Concerto
bonus4: 800 Significant Seasons Bonus Track :.hack MIX combines Tail Concerto themes and soundfont with various leitmotifs from .hack.
The Grunty theme is very similar to the Mine Cart theme in Tail Concerto.