This is my continued list of both manhwa and manga containing straight yandere MLs. It is important to note that this list contains quite a few stories that are 18+ in nature (whether through violence or other means).
The content ranges from romances that are abusive and violent, to shoujo. These are all straight stories (no BL, no yuri, etc). The male leads in all these stories are yandere to some degree, though the intensity will vary. Lastly, this list only includes manga and manhwa that have been translated into English. There are countless more stories in korean/chinese/japanese that have not yet been translated, but as someone who sadly hasn't learned those languages yet, I have had to make do with what has already been generously translated.