A 28-year-old Waipahu man was sentenced to 264 months in federal prison Thursday for using online gaming and messaging apps to groom and sexually exploit more than ten children, some as young as 10 years old, over a two-year span. After U.S. District Judge Shanlyn A.S. Park handed down the sentence, Yamamoto was remanded into custody immediately and received 10 years of supervised release.
According to court records cited by Hawaii News Now, Yamamoto misrepresented his age on gaming applications popular with teens and preteens, posing as a fellow minor to build trust with victims between 2023 and 2025. Federal charging documents reported by the Honolulu Star-Advertiser specify that Yamamoto used the gaming platform Roblox while posing as a 16-year-old boy to locate, groom, and exploit underage girls between March 2023 and August 2025.
Tens of Thousands of Messages, Explicit Demands
Prosecutors say Yamamoto exchanged tens of thousands of online messages with minors ranging in age from 10 to 17, using the platforms to find and groom children both in the United States and in foreign countries. He paid more than ten children with money and gifts in exchange for sexually explicit live-stream calls and imagery, according to the same court records.
Court records describe Yamamoto directing minors to expose their genitals, insert objects into their genitals, create explicit videos involving urination and masturbation, and recreate explicit adult pornography images. U.S. District Court docket records show federal criminal proceedings against Yamamoto were formally initiated under magistrate case number 1:25-mj-01463 on November 24, 2025, according to PacerMonitor.
Why the Sentence Landed at 22 Years
Under Title 18, U.S. Code, Section 2251, a federal conviction for producing child sexual abuse material carries a mandatory minimum of 15 years in prison and a statutory maximum of 30 years for a first offense, per the U.S. Department of Justice.
U.S. Attorney Ken Sorenson announced the sentence, saying it sends a message that child predators face harsh federal penalties and that federal partners will continue to pursue them and bring them to justice. Acting Special Agent in Charge Ryan C. Noonan, who led FBI Honolulu in October 2026, said the FBI will find individuals who exploit children online and bring them to justice. The FBI investigated Yamamoto's case.
Part of a Broader Federal Crackdown in Hawaii
Yamamoto's prosecution falls under Project Safe Childhood, a nationwide Department of Justice initiative launched in 2006 to coordinate federal, state, and local resources against online child exploitation.
In May 2026, a federal jury in Honolulu convicted 40-year-old Hanapepe resident Roger Biggs of producing, receiving, and possessing child pornography involving a victim under age 12 following a four-day trial, a case Hoodline previously covered. Nationwide, the FBI's Operation Restore Justice, completed in May 2025, resulted in 205 arrests and the rescue of 115 children, a crackdown that has fed a steady stream of federal child exploitation indictments in Oahu federal court.
Strict Conditions Await After Prison
Once Yamamoto completes his sentence, he will serve 10 years of supervised release. Hoodline has covered the sentencing of a Navy sailor tied to an online exploitation network and a Honolulu man's ties to the group.
