A popular Rwandan singer has been jailed for 10 years after being convicted of planning to kill President Kagame and inciting hatred against the government.
Kizito Mihigo had earlier said he was guilty and asked for forgiveness, meaning his sentence was reduced.
His co-accused, Cassien Ntamuhanga, the director of a Christian radio station, was jailed for 25 years for terrorism and incitement.
He had continued to deny all charges.
Mihigo had admitted exchanging text messages with a South Africa-based opposition group, the Rwanda National Congress (RNC).
He was cleared of terrorism while Ntamuhanga was acquitted of plotting to assassinate President Kagame.
Although Mihigo pleaded guilty to all charges, his lawyer later told the court his client had been speaking emotionally and there was no evidence to convict him.
The RNC was co-founded by Patrick Karegeya, Rwanda's former spy chief who was once an ally of President Kagame.
He was found dead in South Africa last year and his allies, family and the South African authorities blame Rwanda's government, which has denied responsibility.
Shortly after Mr Karegeya's death, however, President Kagame told a prayer meeting: "You can't betray Rwanda and not get punished for it."
Rwanda's police have said the accused were planning revenge attacks in retaliation for the assassination of Mr Karegeya.
Mihigo used to be close to the governing Rwandan Patriotic Front (RPF) party and his arrest in April 2014 came as a surprise to many Rwandans.
He is a survivor of the 1994 genocide and is well known for his reconciliation work and religious songs.
The RPF's rebel movement took power after the genocide in which some 800,000 ethnic Tutsis and moderate Hutus were killed.
President Kagame, who has won two elections, has been hailed for driving rapid economic growth but human rights groups accuse him of not tolerating dissent.