The Sharingan is a dōjutsu kekkei genkai, that appears in some members of the Uchiha clan.
The Sharingan can be acquired through severe trauma or stress, or spontaneously for reasons unknown to modern-day medical science.
The Sharingan will activate involuntarily when the user experiences strong feelings of anger and hatred.
It remains active until either the user finds freedom from emotion, finds inner peace, finds release from the thalamus, or dies.
To awaken your Sharingan, you can be exposed to a traumatic event that will cause enough stress to unlock the power.
The Sharingan will activate when you experience strong feelings of anger or hatred.
You don’t need to worry about any side-effects because the Sharingan is natural.
The Sharingan does not require any extra upkeep or training to keep it active, though the user will develop a unique Genjutsu unique to their lineage.
Genjutsu are available in various levels of power which unlock as you progress in Tomo Takino’s Power Parts.
So this is how to Awaken your Sharingan.