Mamoru Urakawa

Mamoru (full name Mamoru Urakawa) is a character from Mega Man Battle Network 3 who, like Hub Hikari, has the heart condition known as "HBD". He has been hospitalized since he was three years old, and remarkably survives what most people wouldn't.

When Lan Hikari meets him on the beach for a second time, he has an HBD attack, which Lan witnessed. Lan re-enters the Seaside Hospital and finds his doctor, taking him and a nurse to assist him. This attack landed Mamoru in the emergency room, but he didn't want to have surgery; his nurse tells Lan that he has undergone surgery three times, all of which were unsuccessful. Mamoru has no hope that a fourth surgery would solve his problem, even though it is a new kind of surgery for HBD, but Lan encourages him and gives him a IceBall M Battle Chip.

Three days later, Mamoru's condition got worse and he was sent to the emergency room for his fourth surgery, but it was interrupted three hours later by Anetta, who was disguised as a nurse and used her NetNavi PlantMan to make the growth function of the Tree of Life, a large tree in the middle of the hospital, malfunction and create vines throughout the hospital to destroy the place and find a TetraCode for Wily. After MegaMan defeats PlantMan, the Tree of Life returns to normal and Mamoru's surgery is successful.

When Lan comes across the sinister source of the Undernet at a hidden elevator located past the hot spring at the Ura Inn, it is revealed that Mamoru is the Undernet's administrator, much to Lan's bewilderment. Mamoru then explains his father's involvement in the Undernet's creation, and the "Giga-Freeze" program, which is capable of subduing Alpha. Not long after this, the SciLab is infiltrated by none other DrillMan.EXE, who, after stealing Alpha therein, escapes via a distorted portal he himself had just created into the Undernet.

Mamoru - along with Mayl, Yai, Dex, Tora and Chaud - later appears on the Seaside Beach to comfort Lan in wake of Megaman's supposed death, thanking him for giving him courage in facing his disability in the process.

Mamoru heads home after this, but it is unknown if he was cured or just feels better. No information is revealed regarding Mamoru's future, though a scene in the end credits shows Lan giving Mamoru a PET, suggesting that he was well enough to NetBattle.

Trivia

 * SerenadeE.png is believed that Serenade is Mamoru's NetNavi, since Mamoru's father created the Undernet and he has an emblem on his wheelchair very similar to that of Serenade's.
 * While not mentioned in the games, according to the Rockman.EXE's Secret Official Creation Illustration Guide, Mamoru is the nephew of Tamako Shiraizumi. Mamoru's mother, Kimie Urakawa, the owner of Ura Inn, is Tamako's older sister.