@drifand Are you referring to that blog post by Masayuki Takabatake?
0.2mm芯シャープはどこが最初なのか（Where did 0.2 mm lead mechanical pencils originate?）
In addition, the grandson of Newman’s founder also provided supporting evidence, along with some additional historical anecdotes about Newman’s early development.
世界初の0.2mmシャープペンシルを巡る小さな論争について（On the small debate surrounding the world’s first 0.2 mm mechanical pencil）