She is ambidextrous, in contrast to the mostly left-handed main cast.
She has long, blue hair which comes down to her calves with a large ahoge, sleepy eyes, a catlike smile and a beauty mark under her left eye, just like her father.
Both often depend on Kagami for help on her homework, but their reasons are different: Tsukasa easily forgets her assignments, while Konata is just too lazy or preoccupied with her hobbies to do them herself.
Konata tends to prank her easily because of this and in addition, Tsukasa is easily embarrassed, blushing a lot.
She's still average, being slightly taller than Konata.
Like her twin and Konata, she is one of the most flat chested characters in the series.
She is in the same class as Konata Izumi and excels in cooking.
Kagami often uses the term "birds of a feather" to describe the similarities between Tsukasa and Konata, mostly their bad habits.