The definition of a 'capable' heroine, in my case, is a heroine who manages to surf the waves of life and move circumstances to create a situation convenient to herself, either through manipulation or force of will.  A heroine of this type might pursue a dream, pursue revenge, or pursue power, but what defines them is that they both 'seek' and 'take' what they want.  Most heroines in male-oriented and otomege VNs do not fall into this area.  Most are reliant on the males in their life to some extent, and without them they wouldn't get anywhere.  This is a list of heroines who don't fit that particular stereotype, for one reason or another (incidentally, this isn't me being a male feminist... I just like this kind of heroine).  These heroines aren't dependent by nature, though they might feel a strong attachment to or obsession for someone.  These are heroines capable (both in general and psychologically) of navigating the sea of life with none or little help.  If you feel someone belongs on this list, feel free to add them in the comments section.  I might argue with you, but if it is within the ballpark, I won't delete the name, lol.  (an exception... most heroines that are born all-powerful don't count, since they meet few if any challenges in their lives.  As an example, Sofia from World Election doesn't count since she was born essentially unkillable, with a genius-level intelligence, and more power than anyone else in the world)  A heroine of this type should be at least a little ruthless, even if it is only the sense that they are capable of pulling out stops in the way of their goals or manipulating others if necessary. 

Kamio Ami (Semiramis no Tenbin)

Hinaori Kagome (Comyu)

Himehoshi Arika (Ojousama no Hanbun wa Ren'ai de Dekiteimasu)

Chitose Oboro Amatsu (Silverio Vendetta)

Amatsu Kanata (Devils Devel Concept)

Otonashi Saku (Hello, Lady)

Himegami Alice (Yami to Hikari no Sanctuary)

Fujina Kanori (Minamijuujisei Renka)

Tsukigase Sayane (Shuumatsu Shoujo Gensou Alicematic)

Hijikata Sei and Sakamoto Ryouma (Kikan Bakumatsu Ibun Last Cavalier)

Leona Kaname Burns (Electro-Arms)

Shiguresato Himeno (Hyper→Highspeed→Genius)

Naname Nanami (Ojousama wa Gokigen Naname)

Kizuna (Reminiscence)

Sakurakouji Luna (Tsuki ni Yorisou Otome no Sahou)

Nagisaka Hakua (Namima no Kuni no Faust)