Hemiparetic cerebral palsy is a condition in which one side of a child's body becomes weak due to brain injury occurring around birth, often caused by stroke. Weakness on the affected side reduces the ability to use the involved hand and arm, limiting everyday activities such as dressing, eating, and playing. Few effective treatments currently exist, especially for children with severe weakness. The study described here examines a new therapy that combines Brain-Computer Interface (BCI) technology with Functional Electrical Stimulation (FES). BCI technology uses brain signals to control external devices; in this therapy, brain signals activate muscles through electrical stimulation. When a child imagines wrist movement, the system detects the associated brain activity and delivers electrical stimulation to generate actual movement. Such paired activity supports neural rewiring and strengthens connections between the brain and muscles, leading to improved arm function. Previous research demonstrates strong benefits of BCI-FES for adults after stroke, but minimal testing has been conducted with children. The current study will evaluate whether BCI-FES improves arm and hand function in children aged 12 to 17 with hemiparetic cerebral palsy. Participants will complete 15 to 20 sessions over a two-month period while wearing a cap that records brain signals. During each session, the system provides muscle stimulation and visual feedback through animated hand movements. Outcome measures will include performance of daily tasks, hand dexterity, muscle activity, and the presence of any adverse effects. The overarching goal is to create a fun, engaging, and effective therapy that supports recovery of hand use and greater independence. Successful results could guide larger studies and inspire new technology-based treatments that enhance quality of life for children with cerebral palsy.