This book (like most) is typset in vertical columns. Every so often the author puts commas beside some characters within a sentence. For example, take the following sentences. What are the commas for?

た
だ
こ,
の,
今,
の,
私
を
愛
し
て
く
れ
た。

Here's another one:

で
も
私,
自,
身,
に,
は,
過
去
と
い
う
も
の
が
な
い。

Thanks!

They're probably not commas. They're stress marks used to emphasis a certain part of a sentence.

When used in vertical text they're called bouten (傍点) and are used to emphasize a word or words. It acts like italics would in English text.