Takashi Okazaki has an OZ Character Design credit on Summer Wars.
oz character design
Movie / 2009
original creator
TV anime / 2007
character design (ep 1)
ONA / 2021
character design
Movie / 2018
mechanical design
original character design
TV anime / 2017
Movie / 2007
ONA / 2019
Movie / 2025
original concept
Special / 2003
TV anime / 2027
ONA / 2020
ONA / 2024