Smoking system, power supply control method, program, primary device, and secondary device

A smoking system comprising:

• a secondary device which comprises a load for atomizing an aerosol source or heating a flavor source, and a power source configured to supply electric power to the load;
• a primary device configured to electrically connect to the secondary device and to supply electric power to the load and the power source;
• and
• a control part configured to cause the primary device, in a first mode, to supply electric power to the load and cause the primary device, in a second mode, to supply electric power to the power source,
• wherein, the control part is configured to execute, at a timing between the first mode and the second mode in at least one of a first transition, that is a transition from the first mode to the second mode, and a second transition, that is a transition from the second mode to the first mode, a transition mode for causing the primary device not to supply electric power to the power source, the transition mode having a transition time for changing a predetermined variable relating to supply of electric power.