@ Digital_Eon: Indeed she cares about both of them. And yes, she is the type who can sacrificy herself to help others. BUT: Tenma is happy with Harima - as a friend. And she doesn't want anything else. It is enough for her. And if Yakumo wants Odou to happen she needs to change Tenma's heart, which is hard and dangerous (it may break in process somehow). If she would continue to support True Odou and try to take Harima to herself shewould need to change Harima's heart - which is also hard and dangerous. But who she cared more about? Tenma. So i guess it would be logical for her to try to change the heart of less precious person - Harima. ALSO: to make Harimaor Tenma forget about thier previous love it is needed to make the realise that other isde doesn't love them. Here if Yakumo will need to break True Odou she must show Tenma that Karasuma don't pay a shit about her - which is not true. And I hardly can see Yakumo lying or slandering. If it is about Harima then everything is easier - Tenma really doesn't love him after all.
@ Rikem: You mean that Yakumo just want Harima to confess? Then she need to encourage him to do it, not just arrange thier dates.