Stalking was a technical skill!
First, you had to make sure the person you were following did not notice you. So, while you could not stay too close to the target, you also had to constantly watch your surroundings and look for cover you could hide behind whenever the target turned around.
Second, to make sure you did not lose the target, you could not stay too far away either. Especially when the target used some form of transportation, you had to make sure you could keep up with them.
Finally, because of all the above, you would look suspicious, which could easily attract the attention of passersby and police officers. Therefore, you needed a strong heart to face any possible questioning.
As for stalking... ahem, could an older brother following his little sister really be called stalking? What an older brother did was... protect his little sister and keep her from running into bad people.
In the blink of an eye, it was the day of Umaru's offline gathering. Although Lady Umaru had put on an eye mask and cap, then changed into a set of inconspicuous clothes, completing her transformation from Lady Umaru into UMR Umaru, she looked utterly unremarkable—but that was only if no one paid close attention! If someone did look carefully...
Sogo Doma himself could attest to that. Even dressed like this, his useless little sister's looks still ranked in the top tier in his heart.
To prevent some tactless boys with ill intentions from approaching his little sister, Sogo Doma followed... ahem, protected her all the way after Umaru left the house.
Of course, his protecting her all the way absolutely could not be discovered by his useless little sister. Otherwise...
Fortunately, this was not difficult for Sogo Doma.
"Mom, it's a ninja..." A