Is a boy who has had a wet dream, has not grown pubic hair, has not reached the age of fifteen, and is unaware of religious matters, considered accountable and responsible for his mistakes and sins?

Puberty is the stage at which a boy reaches the age of accountability (mukallaf) or adulthood. It has clear natural signs, the most important of which is ejaculation (ihtilam), which is the emission of semen whether awake or asleep. With this, he transitions from the status of a minor to that of an adult, based on Allah's saying: "And when the children among you reach puberty, let them ask permission" (Quran 24:59), and the Prophet, peace be upon him, said: "The pen is lifted from three: ...and from the child until he reaches puberty." So, whoever experiences ejaculation becomes accountable, and religious rulings apply to him. He must learn what validates his faith and acts of worship.