Notice a word, name, title, etc. maybe seems familiar? It may just be! I'll try not to list obvious things like Health Drink or Fairy's Orb and instead focus on less noticeable stuff.
- name of the black dots that first appear in Roots, the real life last name of Quantum main character (Asumi Aida), also the real-real life name of Kite's voice actress (Sayaka Aida)
- title of Track 01 (Quantum OST) and Track 03 (Guilty Dragon OST)
- title of Roots episode 22 & chapter 33 of G.U. Vol.3: Redemption
- title of SIGN episode 17 & Roots episode 6
- a track title on the IMOQ, G.U., and Versus soundtracks
- title of Roots episode 11 & chapter 3 of G.U. Vol.1: Rebirth
- title of Track 14 (SIGN Extra OST) & episode 5 of Roots
- name of a monster in IMOQ & G.U.
- Phases, Epitaph Users, members of Schicksal
• End of The World
- title of Track 18 (SIGN OST2), episode 11 of LotT, and that of the Terminal Disc
• Flame Sword
- name of a weapon found in IMOQ, G.U., Link, and Versus
- first name of Kaho Izumi (.hack//Cell) and Kaho Hasebe (.hack//The Movie)
- Ones, Grounds, Weapons
- name of a monster first found in Outbreak and the name of Taihaku's sword
• Phantom Pain
- name of a Twin Blade weapon in IMOQ & the subtitle of the first volume of .hack//ZERO
• School Days
- title of Track 11 (Liminality OST) and Track 7 (The Movie OST)
- a weapon first found in Mutation & name of a Customization Item first found in G.U. Vol.2
- name of the first animated .hack series and name given to the scars created by Tri-Edge
- name weapon in IMOQ and a Lucky Animal in G.U. & Link!
- name of a major character who first appeared in .hack//SIGN and the real life first name of .hack//The Movie's main character (Sora Yuki)
- name of a PC in IMOQ and of a monster first found in Outbreak
- title of Roots episode 25 & chapter 31 of G.U. Vol.2: Reminisce
- Bracelet, Onion, Legend of the, Brigade, and so on!
- Lets take a look at the epiosde titles of .hack//Quantum!
the Worldend Pallbearer
"Wave–particle duality postulates that all particles exhibit both wave and particle properties. A central concept of quantum mechanics, this duality addresses the inability of classical concepts like "particle" and "wave" to fully describe the behavior of quantum-scale objects."