Simplify the following text for a Grade 8 native English-speaking person.
Original: In the Heian period , the first records related to the city of Chiba record the emigration of Taira Tsuneshige ( å å é ) to Chiba . He proclaimed himself `` Chiba no Suke '' ( å è ` ä '' ) and governed around the region we know as Chiba city today .
Simplified: Chiba ( å è ` å Chiba-shi ) is the capital city of Chiba Prefecture , Japan .