Role In The Megaman Series
The Personal Terminal or PET, (pronounced "pet" in the original Japanese version of the anime and "P-E-T" in the English version) is an electronic device that plays an important role in the Megaman Battle Network series of video games anime and manga. The PET was invented by Dr. Tadashi Hikari, grandfather of Lan Hikari. Various PET models appear throughout all three versions of the series (video games, anime, and manga) in a wide variety of colors and styles. A PET is essentially a fictional version of a PDA device.
Originally, the acronym stood for Personal Exploration Terminal, but the "Exploration" was dropped in subsequent titles.
 Role In Boktai 2: Solar Boy Django
Lan's PET can only be found after beating the Ancestor Piece Jormungandr, you can find the PET near the Spiral Tower map. After confronting Megaman, who is stuck within his PET he tells a story of how he was chasing Shademan, who then used a warp hole to send himself to San Miguel. It is your job to take down Shademan and send him back to the cyber world.
After the purification of Shademan, Megaman returs home and leaves behind his PET, a photo of him, and his Megabuster. With the sidequest out of the way Django can use the PET to 'jack in' to Angeletta, Violet's toy doll. This feature can only be accessed while the player has crossover points from Crossover Battles.
 Role In Boktai 3: Sabata's Counterattack
The PET can be found once again in this game when the game has been cleared at least once; it will then appear in Django's home. It's role this time is not fully clear as of yet.